CEUS Bosniak Classification-Time for Differentiation and Change in Renal Cyst Surveillance.
Cancers
It is time for a change. CEUS is an established method that should be much more actively included in renal cyst monitoring strategies. This review compares the accuracies, strengths, and weaknesses of CEUS, CECT, and MRI in the classification of renal cysts. In order to avoid overstaging by CEUS, a further differentiation of classes IIF, III, and IV is required. A further development in the refinement of the CEUS-Bosniak classification aims to integrate CEUS more closely into the monitoring of renal cysts and to develop new and complex monitoring algorithms.
10.3390/cancers15194709
EFSUMB 2020 Proposal for a Contrast-Enhanced Ultrasound-Adapted Bosniak Cyst Categorization - Position Statement.
Cantisani Vito,Bertolotto Michele,Clevert Dirk-André,Correas Jean-Michel,Drudi Francesco Maria,Fischer Thomas,Gilja Odd Helge,Granata Antonio,Graumann Ole,Harvey Christopher J,Ignee Andre,Jenssen Christian,Lerchbaumer Markus Herbert,Ragel Matthew,Saftoiu Adrian,Serra Andreas L,Stock Konrad Friedrich,Webb Jolanta,Sidhu Paul S
Ultraschall in der Medizin (Stuttgart, Germany : 1980)
The well-established Bosniak renal cyst classification is based on contrast-enhanced computed tomography determining the malignant potential of cystic renal lesions. Ultrasound has not been incorporated into this pathway. However, the development of ultrasound contrast agents coupled with the superior resolution of ultrasound makes it possible to redefine the imaging of cystic renal lesions. In this position statement, an EFSUMB Expert Task Force reviews, analyzes, and describes the accumulated knowledge and limitations and presents the current position on the use of ultrasound contrast agents in the evaluation of cystic renal lesions.
10.1055/a-1300-1727
Ultrasound-based "CEUS-Bosniak"classification for cystic renal lesions: an 8-year clinical experience.
World journal of urology
PURPOSE:Renal cysts comprise benign and malignant entities. Risk assessment profits from CT/MRI imaging using the Bosniak classification. While Bosniak-IIF, -III, and -IV cover complex cyst variants, Bosniak-IIF and -III stand out due to notorious overestimation. Contrast-enhanced ultrasound (CEUS) is promising to overcome this deficit but warrants standardization. This study addresses the benefits of a combined CEUS and CT/MRI evaluation of renal cysts. The study provides a realistic account of kidney tumor boards' intricacies in trying to validate renal cysts. METHODS:247 patients were examined over 8 years. CEUS lesions were graded according to CEUS-Bosniak (IIF, III, IV). 55 lesions were resected, CEUS-Bosniak- and CT/MRI-Bosniak-classification were correlated with histopathological diagnosis. Interobserver agreement between the classifications was evaluated statistically. 105 lesions were followed by ultrasound, and change in CEUS-Bosniak-types and lesion size were documented. RESULTS:146 patients (156 lesions) were included. CEUS classified 67 lesions as CEUS-Bosniak-IIF, 44 as CEUS-Bosniak-III, and 45 as CEUS-Bosniak-IV. Histopathology of 55 resected lesions revealed benign cysts in all CEUS-Bosniak-IIF lesions (2/2), 40% of CEUS-Bosniak-III and 8% of CEUS-Bosniak-IV, whereas malignancy was uncovered in 60% of CEUS-Bosniak-III and 92% of CEUS-Bosniak-IV. Overall, CEUS-Bosniak-types matched CT/MRI-Bosniak types in 58% (fair agreement, κ = 0.28). CEUS-Bosniak resulted in higher stages than CT/MRI-Bosniak (40%). Ultrasound follow-up of 105 lesions detected no relevant differences between CEUS-Bosniak-types concerning cysts size. 99% of lesions showed the same CEUS-Bosniak-type. CONCLUSION:The CEUS-Bosniak classification is an essential tool in clinical practice to differentiate and monitor renal cystic lesions and empowers diagnostic work-up and patient care.
10.1007/s00345-022-04094-0
Safety and effectiveness of laparoscopic renal biopsy: a single-center review and meta-analysis.
Renal failure
BACKGROUND:While renal biopsy remains the preferred diagnostic method for assessing proteinuria, hematuria, or renal failure, laparoscopic renal biopsy (LRB) can serve as an alternative for high-risk patients when percutaneous kidney biopsy (PKB) is not recommended. This study was aimed to evaluate the safety of LRB. METHODS:In study 1, Fourteen patients from January 2021 to January 2023 had a LRB taken for various indications, such as morbid obesity, abnormal kidney construction, uncontrolled hypertension, and coagulopathy. We also conducted a Meta-analysis of the success rate and complication rate of previous LRB in study 2. RESULTS:All the patients completed biopsies and adequate renal tissues were obtained. The success rate was 100%. The median number of glomeruli obtained was 22.5 (range:12.0, 45.0). The complication rate was 7.1% (urinary tract infection). There were no significant differences between levels of hemoglobin, serum creatinine, and urinary NAGL before and after surgery. In the meta-analysis, the success rate of operation, satisfactory rate of sample, and complication rate of surgery were 99.9%, 99.1%, and 2.6% respectively. CONCLUSION:LRB can achieve a good success rate and specimen retrieval and does not increase the risk of complications for high-risk patients. It can present as one of the alternative methods for patients with glomerular diseases.
10.1080/0886022X.2024.2312536
Surgical Outcomes of Hugo™ RAS Robot-Assisted Partial Nephrectomy for Cystic Renal Masses: Technique and Initial Experience.
Journal of clinical medicine
: The Hugo™ Robot-Assisted Surgery (RAS) system is a new cutting-edge robotic platform designed for clinical applications. Nevertheless, its application for cystic renal tumors has not yet been thoroughly investigated. In this context, we present an initial series of Robot-Assisted Partial Nephrectomy (RAPN) procedures carried out using the Hugo™ RAS system for cystic renal masses. : Between October 2022 and January 2024, twenty-seven RAPN procedures for renal tumors were performed at Fondazione Policlinico Universitario Campus Bio-Medico. Our prospective board-approved dataset was queried for "cystic features" (n = 12). Perioperative data were collected. The eGFR was calculated according to the CKD-EPI formula. Post-operative complications were reported according to the Clavien-Dindo classification. Computed tomography (CT) scans for follow-up were performed according to the EAU guidelines. Trifecta was defined as the coexistence of negative surgical margin status, no Clavien-Dindo grade ≥ 3 complications, and eGFR decline ≤ 30%. : All the patients successfully underwent RAPN without the need for conversion or additional port placement. The median docking and console time were 5.5 (IQR, 4-6) and 79.5 min (IQR, 58-91 min), respectively. No intraoperative complications occurred, as well as clashes between instruments or with the bedside assistant. Two minor postoperative complications were recorded (Clavien-Dindo II). At discharge, serum creatinine and eGFR were comparable to preoperative values. Only one patient (8.4%) displayed positive surgical margins. The rate of trifecta achievement was 91.7%. : RAPN for cystic renal masses using the novel Hugo™ RAS system can be safely and effectively performed. This robotic system provided satisfactory peri-operative outcomes, preserving renal function and displaying low postoperative complications and a high trifecta rate achievement.
10.3390/jcm13123595
Laparoscopic nephron-sparing surgery for complex renal cystic lesions: a single-center experience.
Frontiers in oncology
Objectives:This study aimed to explore the feasibility and safety of laparoscopic nephron-sparing surgery (LNSS) for complex renal cystic lesions. Methods:A retrospective study was conducted on 83 cases of complex renal cystic lesions treated with LNSS in our hospital. There were 32 men and 51 women, ranging in age from 24 to 73 years (average, 47.22 ± 9.03 years). The diameter of the cysts was 1.5-5.9 cm (average, 3.44 ± 0.86cm). According to the Bosniak classification, there were 15 cases of type II, 23 cases of type IIF, 29 cases of type III, and 16 cases of type IV complex renal cystic lesions. According to clinical classification based on the difficulty of laparoscopic partial nephrectomy and the depth of the lesion, the 83 complex renal cystic lesions were divided into 48 cases of the extra-renal type, 15 cases of the centrally located type, seven cases of the renal sinus type, and 13 cases of the renal hilum type. Results:Laparoscopic partial nephrectomy was successful in all 83 patients. The surgical time was 35-102 min (average, 52.13 ± 14.38 min), the intraoperative bleeding volume was 10-200 ml (average, 27.25 ± 12.26 ml), and the renal artery occlusion time was 12-28 min (average, 12.46 ± 4.45 min). There was no significant change in creatinine before and after surgery. The postoperative pathological results showed 71 cases of renal clear cell carcinoma, five cases of low malignant potential multilocular cystic renal tumors, and seven cases of pure renal cysts with all margins negative. Conclusions:There is potential for the malignant transformation of complex renal cysts into renal cell carcinoma. For complex renal cysts classified as Bosniak IIF or higher, surgical intervention is recommended, and LNSS is safe and effective. The complexity of the surgical procedure varies depending on the location classification of the complex renal cysts.
10.3389/fonc.2024.1398347
Meta-analysis of clinical outcomes of robot-assisted partial nephrectomy and classical open partial nephrectomy.
International journal of surgery (London, England)
BACKGROUND:Robotic-assisted partial nephrectomy (RAPN) has emerged as a promising alternative to classical partial nephrectomy (CPN). AIM:This study aimed to compare the outcomes of RAPN and CPN for treating localized renal tumors through a meta-analysis of available literature. METHODS:Chinese databases, such as CNKI, Chinese Science and Technology Periodicals Database (VIP), and Wanfang Full-text Database, were searched using Chinese search terms, and all published articles on PubMed and Web of Science were searched using English search terms. Articles on Localized Renal Tumors were included. RevMan5.3 software was used for meta-analysis. The funnel plots were drawn using Stata software to assess publication bias. OUTCOMES:This study aimed to identify the differences between robotic-assisted partial nephrectomy and classic partial nephrectomy in patients with localized renal tumors. RESULTS:In total, 67 articles with 17 677 patients were included. The results demonstrate the advantages of RAPN over CPN for localized renal tumors. Compared to CPN and RAPN had significant differences in intraoperative blood loss, hospital stay duration, incidence of perioperative complications, and proportion of patients requiring blood transfusion. Regarding surgical outcomes, RAPN showed more favorable results regarding the incidence of positive resection margins, postoperative decline in glomerular filtration rate (GFR), postoperative local recurrence rate, and proportion of Trifecta achieved. However, there was no significant difference between RAPN and CPN regarding 5-year tumor-specific survival rates. CLINICAL IMPLICATIONS:The study suggests that robotic-assisted partial nephrectomy is a viable alternative to classic surgery for renal tumors. STRENGTHS AND LIMITATIONS:The strengths of this study are the use of a comprehensive search strategy and the inclusion of studies published in both English and Chinese. The limitations of this study are the small sample size and the need for long-term follow-up data. CONCLUSION:RAPN and CPN have similar overall survival outcomes for treating localized renal tumors. However, RAPN may offer advantages in terms of perioperative outcomes and preservation of renal function. Further studies are needed to confirm these findings and to identify the optimal surgical approach for individual patients.
10.1097/JS9.0000000000001324
Growth Kinetics and Progression Rate of Bosniak Classification Version 2019 Class III and IV Cystic Renal Masses on Imaging Surveillance.
AJR. American journal of roentgenology
Active surveillance is increasingly used as first-line management for localized renal masses. Triggers for intervention primarily reflect growth kinetics, which have been poorly investigated for cystic masses defined by the Bosniak classification version 2019 (v2019). The purpose of this study was to determine growth kinetics and incidence rates of progression of class III and IV cystic renal masses, as defined by the Bosniak classification v2019. This retrospective study included 105 patients (68 men, 37 women; median age, 67 years) with 112 Bosniak v2019 class III or IV cystic renal masses on baseline renal mass protocol CT or MRI examinations performed from January 2005 to September 2021. Mass dimensions were measured. Progression was defined as any of the following: linear growth rate (LGR) of 5 mm/y or greater (representing the clinical guideline threshold for intervention), volume doubling time less than 1 year, T category increase, or N1 or M1 disease. Class III and IV masses were compared. Time to progression was estimated using Kaplan-Meier curve analysis. At baseline, 58 masses were class III and 54 were class IV. Median follow-up was 403 days. Median LGR for class III masses was 0.0 mm/y (interquartile range [IQR], -1.3 to 1.8 mm/y) and for class IV masses was 2.3 mm/y (IQR, 0.0-5.7 mm/y) ( < .001). LGR was at least 5 mm/y in four (7%) class III masses and 15 (28%) class IV masses ( = .005). Two patients, both with class IV masses, developed distant metastases. Incidence rate of progression for class III masses was 11.0 (95% CI, 4.5-22.8) and for class IV masses 73.6 (95% CI, 47.8-108.7) per 100,000 person-days of follow-up. Median time to progression was undefined for class III masses given the small number of progression events and 710 days for class IV masses. Hazard ratio of progression for class IV relative to class III masses was 5.1 (95% CI, 2.5-10.8; < .001). During active surveillance of cystic masses evaluated using the Bosniak classification v2019, class IV masses grew faster and were more likely to progress than class III masses. In comparison with current active surveillance guidelines that treat class III and IV masses similarly, future iterations may incorporate relatively more intensive surveillance for class IV masses.
10.2214/AJR.22.27400
Outcomes and complications related to the management of Bosniak cystic renal lesions.
Smith Andrew Dennis,Allen Brian C,Sanyal Rupan,Carson James Daniel,Zhang Haowei,Williams Jason Henry,Collins Clinton,Griswold Michael,Zhang Xu
AJR. American journal of roentgenology
OBJECTIVE:The objective of our study was to evaluate outcomes and complications related to the management of Bosniak category IIF, III, and IV renal cysts. MATERIALS AND METHODS:For this multiinstitutional retrospective study, a Web-based Research Electronic Data Capture (REDCap) data registry was used to record data of 286 adult patients with 312 prospectively classified Bosniak IIF, III, and IV renal cysts diagnosed between January 2000 and October 2011. Included patients were managed by surgery (n = 86), percutaneous ablation (n = 19), or imaging surveillance of 1 year or more (n = 181). The median number of years of clinical surveillance was 2.4 years (range, 0-11.7 years), 2.6 years (range, 0.4-11.4 years), and 3.2 years (range, 1.1-11.6 years) for patients managed by surgery, ablation, and imaging surveillance, respectively. Pathologic and survival outcomes and complications related to management were evaluated. RESULTS:The malignancy rate at surgical pathology was 38% (3/8) for Bosniak IIF, 40% (29/72) for Bosniak III, and 90% (18/20) for Bosniak IV renal cysts. There were no metastases or deaths (0/144) directly related to Bosniak IIF renal cysts. There were no deaths (0/113) directly related to Bosniak III renal cysts, although one patient (1/113) developed local progression and lung metastases after thermal ablation. One patient with a Bosniak IV renal cyst (1/29) presented with and died of metastatic disease. Moderate to severe complications occurred in 19% (16/86), 5% (1/19), and 0% (0/181) of patients managed by surgery, ablation, and imaging surveillance, respectively (p < 0.0001). Severe complications occurred in 7% (6/86) of surgical patients and included multiorgan failure (n = 2), acute myocardial infarction (n = 1), acute ischemic stroke (n = 1), conversion to hemodialysis-dependent chronic kidney disease (n = 1), and postoperative severe hemorrhage (n = 1). CONCLUSION:There were no deaths from Bosniak IIF or III renal cysts regardless of management approach. Moderate to severe complications are frequent in patients managed by surgery.
10.2214/AJR.14.13149
Imaging-guided radiofrequency ablation of cystic renal neoplasms.
Allen Brian C,Chen Michael Y,Childs David D,Zagoria Ronald J
AJR. American journal of roentgenology
OBJECTIVE:The purpose of this article is to determine whether percutaneous radiofrequency ablation (RFA) is effective and safe for the treatment of cystic renal neoplasms. MATERIALS AND METHODS:This is a retrospective review of imaging-guided RFA of Bosniak III and IV cysts from one institution. Thirty-eight subjects (19 men and 19 women; mean age, 71 years; age range, 46-95 years) underwent RFA of 40 cystic neoplasms (Bosniak III, n = 25; Bosniak IV, n = 15). Percutaneous biopsy was performed in 90% (36/40) of lesions. For patients with imaging follow-up of at least 1 year (n = 21), the mean duration of surveillance was 2.8 years (range, 1-6.5 years). The electronic medical record was reviewed for complications related to the procedure. Estimated glomerular filtration rate (GFR) was measured before RFA and at the last follow-up visit more than 6 months after the RFA session. RESULTS:According to percutaneous biopsy, 61.1% (22/36) of lesions were malignant, and 38.9% (14/36) of biopsies were inconclusive. There was no local tumor progression, and no subjects developed metastatic disease. One subject developed a new solid renal mass during the course of follow-up. Minor complications occurred in 5.3% (2/38) of ablations and included dysuria and mild hydronephrosis related to a blood clot in the ureter. There was one major complication (2.6%), a case of flash pulmonary edema. On average, estimated GFR decreased by 2.5 mL/min/1.73 m(2). CONCLUSION:Imaging-guided RFA is an effective and safe treatment of Bosniak III and IV cystic renal neoplasms with outcomes comparable to those of surgical therapies.
10.2214/AJR.12.9336
Efficacy of imaging-guided percutaneous radiofrequency ablation for the treatment of biopsy-proven malignant cystic renal masses.
Felker Ely R,Lee-Felker Stephanie A,Alpern Lousine,Lu David,Raman Steven S
AJR. American journal of roentgenology
OBJECTIVE:The purpose of this study was to determine the efficacy of imaging-guided percutaneous radiofrequency ablation (RFA) for the treatment of Bosniak category III and IV cystic renal lesions. MATERIALS AND METHODS:Our database was searched to assemble a cohort of biopsy-proven malignant Bosniak category III and IV cystic renal lesions that were treated with imaging-guided percutaneous RFA from 2004 to 2012. The clinical history, imaging features, procedural complications, pathologic results, imaging follow-up, and clinical outcomes of each case were reviewed. RESULTS:A total of 16 patients and 23 biopsy-proven malignant cystic renal lesions were included; two patients with von Hippel-Lindau syndrome had four and three treated lesions each, and a patient with multiple renal tumors had three treated lesions. The other 13 patients each had a single lesion. Clinical follow-up ranged from 2 to 110 months (average, 24 months). The primary treatment efficacy of RFA was 91% (21/23 lesions), and the secondary treatment efficacy was 96% (22/23 lesions). A minority of patients experienced partial loss of renal function. There were no complications related to bleeding or tumor seeding. CONCLUSION:Imaging-guided percutaneous RFA is safe and effective for the treatment of Bosniak category III and IV cystic renal lesions.
10.2214/AJR.12.10210
Efficacy, safety and effectiveness of image-guided percutaneous microwave ablation in cystic renal lesions Bosniak III or IV after 24 months follow up.
Carrafiello Gianpaolo,Dionigi Gianlorenzo,Ierardi Anna Maria,Petrillo Mario,Fontana Federico,Floridi Chiara,Boni Luigi,Rovera Francesca,Rausei Stefano,Mangano Alberto,Spampatti Sebastiano,Marconi Alberto,Carcano Giulio,Dionigi Renzo
International journal of surgery (London, England)
PURPOSE OF THE STUDY:The aim of the study was to assess the efficacy, safety and effectiveness of percutaneous image-guided microwave ablation (MWA) in Bosniak category III or IV cystic renal lesions after 24 months follow-up duration. METHODS:Between May 2008 and December 2012, computed tomography (CT)- or ultrasound (US)-guided MWA was performed in 6 patients with 7 cystic renal lesions (range 13.8-27 mm, mean 17.02 mm, SD 8.5 mm) Bosniak category III or IV. The number of treatment sessions, treatment results, lesion size changes and complications were evaluated. Technical success (TS), technical effectiveness (TE), local tumor progression rate (LTPR), cancer-specific survival rate (CSSR) and overall survival rate (OSR) were computed. MAIN FINDINGS:TS was 100% (7/7) and TE was 100%; LTPR was 0%; CSSR and OSR were 100%. No major complications were observed. CONCLUSION:Our preliminary experience with MWA shows a potential role for US/CT-guided percutaneous MWA in treating Bosniak category III or IV cystic renal lesions, as a safe approach to treat selected patients not suitable for surgery.
10.1016/S1743-9191(13)60010-2
Computed Tomography-Guided Microwave Ablation of Cystic Renal Cell Carcinoma: Assessment of Technique and Complications.
Zhou Wenhui,Herwald Sanna E,Arellano Ronald S
Journal of vascular and interventional radiology : JVIR
This report evaluates the techniques and complications of microwave ablation of cystic renal cell carcinoma. Five patients with cystic renal cell carcinoma were treated with microwave ablation between October 2015 and June 2020. Medical records were reviewed to evaluate technique and complications. Technical success and primary technique efficacy both were 100%. There were no complications. Mean follow-up time was 18 months (range, 6-36 months). No local recurrence was identified during the follow-up period. Renal function remained stable at 1 month and the last follow-up. Percutaneous microwave ablation is promising for the nonsurgical management of cystic renal cell carcinoma.
10.1016/j.jvir.2020.12.021
The safety and efficacy of laparoscopic microwave ablation-assisted partial nephrectomy: a new avenue for the treatment of cystic renal tumors.
International journal of hyperthermia : the official journal of European Society for Hyperthermic Oncology, North American Hyperthermia Group
PURPOSE:Clinically, the management of cystic renal masses is tricky. The study aims to evaluate the safety and efficacy of laparoscopic microwave ablation-assisted partial nephrectomy (LMAPN) for cystic renal tumors. METHODS AND MATERIALS:Between November 2017 and January 2022, LMAPN was performed on 43 patients (29 men and 14 women; age range: 22-80 years; median age 54 years) with Bosniak category III ( = 15) or IV ( = 28) cystic renal tumors (size range: 1.2-5.0 cm; mean size 2.8 cm). The median follow-up period was 26 months (range: 7-56 months). Baseline and perioperative data, pathological features, renal function, postoperative complications and oncologic outcomes were collected and evaluated. RESULTS:Forty-three cystic renal tumors were successfully managed by LMAPN. The mean operating time was 79 min (range: 40-130 min). The mean time of renal pedicle clamping was 19 min (range: 12-25 min). Mean intraoperative blood loss was 28.4 mL (range: 10-80 mL). The mean postoperative hospitalization duration was 4 days (range: 2-6 days). Negative surgical margins were diagnosed in all cases. During the follow-up, no patient appeared with distant metastasis, wound or peritoneal cavity implantation. No major but minor complications of Clavien-Dindo grade I were encountered after the operation. The 1-, 3- and 4-year overall survival rate was 100%, 96.6% and 88.5%, respectively. CONCLUSION:This is the first study focusing on LMAPN for cystic renal tumors, demonstrating its favorable feasibility, safety and disease control. Long-term follow-up is necessary to draw conclusions on the preference and advantages of the new therapeutic approach.
10.1080/02656736.2022.2157499
Robotic partial nephrectomy for cystic renal masses: a comparative analysis of a matched-paired cohort.
Akca Oktay,Zargar Homayoun,Autorino Riccardo,Brandao Luis Felipe,Laydner Humberto,Krishnan Jayram,Samarasekera Dinesh,Li Jianbo,Haber Georges-Pascal,Stein Robert,Kaouk Jihad H
Urology
OBJECTIVE:To compare the outcomes of robotic partial nephrectomy (RPN) for cystic and solid renal neoplasms. METHODS:Our RPN database was queried to identify consecutive patients who underwent RPN for cystic and solid renal masses in the period between July 2007 and July 2013. Cystic renal masses were diagnosed on cross-sectional imaging (computed tomography or magnetic resonance imaging). Matching was done between the patients with cystic renal masses and patients with solid renal masses (1:1 matching) by age, gender, tumor size, and nephrometry score. RESULTS:Of 647 cases, 55 patients with cystic masses (group 1) were matched with 55 patients with solid tumors (group 2). There was no cyst rupture or positive surgical margin observed in group 1. The volume of resected rim of healthy renal parenchyma surrounding the tumor was the same for both groups (P=.9). There was no difference between the groups in terms of percentage of glomerular filtration rate preservation postoperatively (85% vs 86%; P=.94). There was no difference in term of overall complications between the 2 groups. Thirty patients (54.5%) in group 1 and 47 patients (85.5%) in group 2 had renal cell carcinoma (P=.0001). CONCLUSION:RPN can be safely and effectively performed when treating a suspicious cystic renal neoplasm with outcomes resembling those obtained for solid masses. Thus, when a cystic renal mass in encountered, nephron-sparing surgery can be offered and RPN represents an effective tool for this approach.
10.1016/j.urology.2014.03.017
CA9 level in renal cyst fluid: a possible molecular diagnosis of malignant tumours.
Li Guorong,Feng Gang,Cuilleron Muriel,Zhao An,Gentil-Perret Anne,Cottier Michèle,Genin Christian,Tostain Jacques
Histopathology
AIMS:The preoperative differentiation of malignant renal cystic tumours from benign lesions is critical, and it remains a common diagnostic problem. The aim was to examine if the Carbonic anhydrase 9 (CA9) level in cyst fluid can provide a molecular diagnosis of malignant cyst. METHODS AND RESULTS:Twenty-eight patients with a cystic renal mass were included. Fine-needle aspiration was performed to obtain the fluid. Postoperative pathology confirmed that there were 16 cystic renal cell carcinomas. Twelve benign cystic tumours were used as controls. One hundred microlitres of supernatant of cyst fluid was used to measure the CA9 protein level, which was measured by an enzyme-linked immunosorbent assay technique. CA9 was strongly detected and considered as positive in the cyst fluid of all 16 cystic malignant tumours (>1000 pg/ml), whereas its expression was negative in 11/12 benign cystic tumours (<300 pg/ml). The difference in percentages of positive CA9 between malignant and benign renal cystic tumours was significant (P < 0.001). CONCLUSION:The fluid of malignant cystic renal tumours contains a high level of CA9 protein. The measurement of CA9 level in cyst fluid may be used as a molecular diagnosis for differentiation between malignant and benign renal cystic masses.
10.1111/j.1365-2559.2009.03302.x
CA9 as a molecular marker for differential diagnosis of cystic renal tumors.
Li Guorong,Bilal Issam,Gentil-Perret Anne,Feng Gang,Zhao An,Peoc'h Michel,Genin Christian,Tostain Jacques,Gigante Marc
Urologic oncology
OBJECTIVE:CA9 is proven to be a powerful marker for clear cell renal cell carcinoma. The studies on CA9 have been limited to solid renal cell carcinomas (RCC). We have conducted a study of CA9 expression in renal cystic tumors. The purpose of the present study was to extend the utility of CA9 for cystic renal tumors. MATERIALS AND METHODS:Immunohistochemistry and enzyme-linked immunosorbent assay (ELISA) were used to detect CA9 expression in cystic renal tumors. Forty-three cystic renal tumors (22 benign and 21 malignant) were included for the immunohistochemical staining. Thirty-six patients with a cystic renal mass (20 malignant and 16 benign cystic tumors) were studied to measure CA9 level in the fluid by ELISA. Sixteen cysts (9 malignant and 7 benign cysts) were subjected both to immunohistochemistry and CA9 measurement in the fluid. RESULTS:Using immunohistochemical staining, all the benign cystic renal tumors including the 18 simple cyst and 4 benign multilocular cystic nephromas did not express CA9. All 13 cystic clear cell RCC were scored as strong staining for CA9. For 8 multilocular clear cell RCC, 7 were scored as strong staining for CA9 and the other one was negative. There was a significant difference in positive percentage (P < 0.001) between the 2 groups of malignant and benign cysts. For the 16 benign cysts, the mean concentration of CA9 in the fluid of cyst was 162 ± 133 pg/ml (median: 0 pg/ml; range: 0-2140 pg/ml). For the 20 malignant renal cystic tumors, the mean concentration of CA9 in the fluid of cyst was 2043 ± 62 pg/ml (median: 2,140 pg/ml; range: 1,112-2,140 pg/ml). There was a significant difference in mean concentration of CA9 between the two groups of malignant and benign cysts (P < 0.001). The presence or absence of CA9 expression measured by immunohistochemistry and ELISA test was concordant in 14 out of 16 cases (88%). CONCLUSIONS:Malignant cystic renal tumors expressed strongly CA9 while the benign renal cysts did not express CA9. CA9 can be detected in the fluid of malignant cystic renal tumors. CA9 is a promising molecular marker to differentiate the malignant cystic renal tumors from the benign cysts.
10.1016/j.urolonc.2010.04.014
Long-Term Surveillance of Complex Cystic Renal Masses and Heterogeneity of Bosniak 3 Lesions.
The Journal of urology
PURPOSE:We sought to better characterize the frequency of Bosniak cyst class changes, identify predictors of change and progression, determine the average growth rate of cysts and validate the safety of active surveillance. MATERIALS AND METHODS:Consecutive patients referred for the management of complex cysts (Bosniak 2F or greater) were included in analysis. All imaging studies were reevaluated and any stage change was reviewed with a blinded genitourinary radiologist. Bosniak 3 cysts were subclassified as 3s-septated enhancing Bosniak cysts and 3n-cysts with wall or septation-only nodularity. A multivariate Cox proportional hazards model was used to identify predictors of the Bosniak classification change. Kaplan-Meier curves were applied to analyze Bosniak cyst progression and regression. RESULTS:A total 140 lesions were included in study, necessitating review of a total of 1,011 abdominal scans in 111 patients. Median followup was 46 months (IQR 23-65.5) and patients underwent a mean of 6.8 diagnostic scans. On multivariate analysis nodular cysts progressed (HR 6.16, 95% CI 2.58-14.72, p <0.00004) and entirely endophytic cysts were less likely to progress (HR 0.21, 95% CI 0.05-0.85, p = 0.028). On Kaplan-Meier analysis Bosniak 3s cysts were more likely to regress while Bosniak 3n cysts were more likely to progress than 3s cysts (p = 0.0178 and 0.0002, respectively). The growth rate of 3n and 2F cysts was 0.19 and 0.11 cm per year (p = 0.0493 and 0.0327, respectively). Locally advanced or metastatic disease did not develop in any patient. CONCLUSIONS:A diagnostic change in Bosniak 3s and 2F cysts is common and Bosniak 3n cysts behave more like Bosniak 4 cysts. Most complex kidney cysts can be safely monitored without intervention and the interval between serial imaging procedures should be increased.
10.1016/j.juro.2018.07.063
The Bosniak renal cyst classification: 25 years later.
Bosniak Morton A
Radiology
In the past 25 years, there have been continuous advances in the diagnosis of disease throughout the body owing to the introduction of new technology and the experience gained with its use. However, the imaging and evaluation of complicated cystic lesions of the kidneys frequently remains a difficult problem. The classification of renal cystic lesions suggested 25 years ago, now referred to as the Bosniak renal cyst classification, remains pertinent to the diagnosis and management of these difficult-to-diagnose complicated cystic masses.
10.1148/radiol.11111595
The current radiological approach to renal cysts.
Bosniak M A
Radiology
The radiologic diagnosis of renal cysts (and their differentiation from renal neoplasms) has come a long way since the 1950s when the approach was surgical exploration, unless clinically contraindicated, for every renal mass detected using urography. Nephrotomography, renal angiography, and cyst puncture have contributed over the ensuing years to the differentiation of cyst from tumor. However, for the most part, sonography and CT (or a combination of these when necessary) have become the main diagnostic techniques for evaluating renal masses, and with their use we have never been more accurate, noninvasive, and relatively economically efficient. The more widespread use of CT has enabled serendipitous discovery of many small renal carcinomas, the removal of which should result in an improvement in the overall cure rate of patients with renal parenchymal neoplasms. On the other hand, we are also discovering many more cysts than we have previously. We must be on guard, therefore, against discovering lesions for which we are unable to establish a radiologic diagnosis of benignity, because this will only increase the need for exploratory surgery once again. It is thus imperative that imaging studies be performed with great care, that diagnoses be based on rigid criteria, and that more experience with difficult lesions be gained so that the proper approach to treatment will be determined. If we are able to accomplish this, then the present radiologic age can be remembered as a time when great advances in the evaluation of renal masses were made, with resultant improved patient management and cure of disease.
10.1148/radiology.158.1.3510019
Bosniak Classification for Complex Renal Cysts Reevaluated: A Systematic Review.
Schoots Ivo G,Zaccai Keren,Hunink Myriam G,Verhagen Paul C M S
The Journal of urology
PURPOSE:We systematically evaluated the Bosniak classification system with malignancy rates of each Bosniak category, and assessed the effectiveness related to surgical treatment and oncologic outcome based on recurrence and/or metastasis. MATERIALS AND METHODS:In a systematic review according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement and the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies) criteria, we selected 39 publications for inclusion in this analysis and categorized them into 1) surgical cohorts-all cysts treated surgically and 2) radiological cohorts-cysts with surgical treatment or radiological followup. RESULTS:A total of 3,036 complex renal cysts were categorized into Bosniak II, IIF, III and IV. In surgical and radiological cohorts pooled estimates showed a malignancy prevalence of 0.51 (0.44, 0.58) in Bosniak III and 0.89 (0.83, 0.92) in Bosniak IV cysts, respectively. Stable Bosniak IIF cysts showed a malignancy rate of less than 1% during radiological followup (surveillance). Bosniak IIF cysts, which showed reclassification to the Bosniak III/IV category during radiological followup (12%), showed malignancy in 85%, comparable to Bosniak IV cysts. The estimated surgical number needed to treat to avoid metastatic disease of Bosniak III and IV cysts was 140 and 40, respectively. CONCLUSIONS:The effectiveness of the Bosniak classification system for complex renal cysts was high in categories II, IIF and IV, but low in category III, and 49% of Bosniak III cysts was overtreated because of a benign outcome. This surgical overtreatment combined with the excellent outcome for Bosniak III cysts may suggest that surveillance is a rational alternative to surgery. This will require further study to assess whether surveillance of Bosniak III cysts will prove safe.
10.1016/j.juro.2016.09.160
Malignancy Rate, Histologic Grade, and Progression of Bosniak Category III and IV Complex Renal Cystic Lesions.
Mousessian Pedro N,Yamauchi Fernando I,Mussi Thais C,Baroni Ronaldo H
AJR. American journal of roentgenology
OBJECTIVE:The primary purpose of this study is to determine the malignancy rate, histologic grade, and initial stage of surgically treated complex renal cysts classified as Bosniak category III or IV. For nonsurgical lesions, a secondary objective was to evaluate lesion progression on follow-up examinations. MATERIALS AND METHODS:We searched our database for cystic lesions classified as Bosniak III or IV category on CT or MRI from January 2008 to April 2016. Surgically resected lesions, per category, were correlated with information on pathologic reports to obtain malignancy rates. For malignant lesions, histologic grade and initial stage were evaluated. Imaging follow-up of at least 2 years was used to evaluate progression of clinically followed lesions. RESULTS:We included 86 lesions in 85 patients in the final analysis. Of the 60 surgically resected lesions (70%), 46 (77%) were malignant and 14 (23%) were benign. Malignancy rates were 72% for Bosniak category III lesions and 86% for Bosniak category IV lesions. Most malignant cysts were early-stage (pT1) cysts with low histologic grades (89% of Bosniak III lesions and 91% of Bosniak IV lesions). Follow-up studies of the surgically resected lesions did not show local recurrence, metastasis, or lymph node enlargement. Among patients with lesions managed by watchful waiting (n = 26), all lesions remained unchanged in terms of size and complexity after at least 2-years of follow-up. CONCLUSION:Although high malignancy rates were observed for both Bosniak category III and IV lesions, our results suggest that such malignant cysts are usually early-stage tumors with a low histologic grade. Lesions that underwent follow-up remained unchanged on control examinations. These findings may indicate low aggressiveness of these lesions, supporting the idea that more conservative approaches may be used.
10.2214/AJR.17.18142
Solitary cyst and clear cell adenocarcinoma of the kidney: report of 2 cases and review of the literature.
Bruun E,Nielsen K
The Journal of urology
We report 2 cases of a solitary simple cyst of the kidney harboring clear cell adenocarcinoma in the wall of the cyst. Cysts of the kidney may be divided into solitary cysts, that is large, unilocular cysts with a thin wall, and multilocular cysts, that is sharply demarcated multilocular epithelial-lined cysts with compression of the adjacent renal parenchyma. There are 4 types of tumor and cyst that occur in the same kidney, and our cases belonged to type 3. Suspicion of malignancy was raised by preoperative cytological examination of the fluid of the cysts. Perioperatively, however, no gross evidence of malignancy was found in either case. Frozen section biopsy in case 1 failed to confirm the diagnosis. The cysts were removed by partial nephrectomy. Patient 1 died within 2 years of widespread metastases. Patient 2 had undergone nephrectomy and was well. Based on the literature and our findings we strongly recommend the surgical approach of partial nephrectomy followed by total nephrectomy when the diagnosis has been confirmed.
10.1016/s0022-5347(17)44902-0
Prevalence of Malignancy and Histopathological Association of Bosniak Classification, Version 2019 Class III and IV Cystic Renal Masses.
Tse Justin R,Shen Luyao,Shen Jody,Yoon Luke,Kamaya Aya
The Journal of urology
PURPOSE:Bosniak Classification, version 2019 (v2019) describes 2 types of class III and IV masses each: 1) thick, wall/septa ≥4 mm (III-WS), 2) obtuse protrusion ≤3 mm (III-OP), 3) obtuse protrusion ≥4 mm (IV-OP), and 4) acute protrusion of any size (IV-AP). The purposes of this study were to determine the prevalence of malignancy and histopathological features of class III and IV masses and subclasses. MATERIALS AND METHODS:In this institutional review board-approved and Health Insurance Portability and Accountability Act-compliant study, 3 fellowship-trained abdominal radiologists (R1-3) reviewed cystic renal masses that had tissue pathology and preoperative renal mass protocol computerized tomography or magnetic resonance imaging. Classes based on v2019 and prior classification systems were retrospectively re-assigned and associated with malignancy, aggressive histologic features (necrosis or high Fuhrman grade) and radiological progression following resection. RESULTS:The final sample included 79 masses (59 malignant, 20 benign) from 74 patients. Based on v2019, prevalence of malignancy ranged from 56% to 61% (mean 60%) for class III and 83% to 83% (mean 83%) for class IV (p=0.036, 0.013, 0.036 for 3 fellowship-trained abdominal radiologists). Prevalence of malignancy within subclasses were: III-WS (overall 49%; range 47%-53%); III-OP (76%; 71%-85%); IV-OP (78%; 75%-87%); IV-AP (87%; 82%-95%; p=0.029, 0.001, 0.005). All readers were more likely to classify malignancies with aggressive histologic features as class IV (88% to 100%) rather than class III (0% to 12%; p=0.012, <0.001, 0.002), corresponding to a negative predictive value of 96% to 100%. After treatment (mean followup length 1,210 days), 1 patient developed metastases. CONCLUSIONS:Bosniak Classification, version 2019 can help risk stratification of class III-IV masses by identifying those likely to be malignant and have aggressive histologic features.
10.1097/JU.0000000000001438
Outcome of surgery in cystic renal cell carcinoma.
Koga S,Nishikido M,Hayashi T,Matsuya F,Saito Y,Kanetake H
Urology
OBJECTIVES:To review cases of cystic renal cell carcinoma treated surgically at our institution and define their clinical and histopathologic features. METHODS:Between 1986 and 1998, 21 patients with cystic renal cell carcinoma were treated surgically. Cystic renal cell carcinoma was categorized using Hartman's classification. RESULTS:Histopathologic examination demonstrated cystic necrosis in 11 patients, multilocular cystic renal cell carcinoma in 9, and unilocular cystic renal cell carcinoma in 1 patient. Tumors were incidentally found during an evaluation of unrelated disease or a general health checkup in 14 patients (67%). The mean tumor size was 5.6 cm (range 0.5 to 12) for cystic necrosis and 5.4 cm (range 2 to 9) for multilocular cystic renal cell carcinoma. All 9 cases of multilocular cystic renal cell carcinoma were of the clear cell type and tumor grade 1. The mean follow-up period was 65 months (range 9 to 141). The 5-year disease-specific survival rates for multilocular cystic renal cell carcinoma and cystic necrosis were 100% and 80%, respectively. CONCLUSIONS:The prognosis for patients with cystic renal cell carcinoma is better than that for patients with solid tumors. In particular, the prognosis of multilocular cystic renal cell carcinoma is excellent. Multilocular cystic renal cell carcinoma represents a distinct subtype of renal cell carcinoma that can be completely cured by surgery.
10.1016/s0090-4295(00)00540-9
Multilocular cystic renal cell carcinoma: a series of 12 cases and review of the literature.
Nassir Anmar,Jollimore Jason,Gupta Rekha,Bell David,Norman Richard
Urology
OBJECTIVES:To assess the presentation and diagnosis of, and treatment options for, multilocular cystic renal cell carcinoma (MCRCC). MCRCC is a rare entity and the true incidence and biologic behavior of MCRCC are not well known. METHODS:We reviewed the pathology files at the Queen Elizabeth II Health Sciences Centre for a 9-year period (1991 to 2000). All cases of RCC with a cystic component were identified. The clinical features, radiologic features, surgical procedure, pathologic features, and follow-up outcomes of the MCRCC cases were studied. RESULTS:We identified 12 cases of MCRCC comprising 3.1% of the RCC cases. The tumor was incidentally found in 67% of the cases. Ultrasonography was found to be a useful screening test, but computed tomography is the imaging study of choice to identify malignant features. Magnetic resonance imaging can be used in equivocal cases. For treatment, radical nephrectomy was done in 58% and partial nephrectomy in 33%. The mean tumor size was 3.4 cm. The mean solid component of the tumor was 9.5%. The mean tumor grade was 1.1. None of the 10 patients (83%) available for follow-up showed any evidence of recurrence. They were followed up for an average of 42.5 months. CONCLUSIONS:MCRCC is an uncommon subtype (3%) of RCC. The term MCRCC should be used exclusively to identify cystic RCC with a small volume (25% or less) of neoplastic clear cells in the cyst walls. The benign clinical course of these lesions suggests that patients may benefit from nephron-sparing surgery.
10.1016/s0090-4295(02)01742-9
Cystic renal cell carcinoma: biology and clinical behavior.
Han Ken-Ryu,Janzen Nicolette K,McWhorter Valerie C,Kim Hyung L,Pantuck Allan J,Zisman Amnon,Figlin Robert A,Dorey Frederick J,Said Jonathan W,Belldegrun Arie S
Urologic oncology
The purpose of the study was to evaluate unilocular and multilocular cystic renal cell carcinoma (cRCC). These tumors are a rare entity, comprising approximately 1 to 2% of all renal tumors, and their true biologic behavior is not well-known. Initial review of renal cell carcinoma (RCC) cases treated at our institution between 1989 and 2001 identified 39 cases of cRCC. However, histopathologic review of these cases by 2 pathologists revealed that only 18 cases met the criteria that all tumors have a cystic component that constitutes at least 75% of the total lesion without evidence of necrosis. These cases were compared to 614 conventional clear cell RCC cases with regards to clinical outcomes. All 18 patients presented with localized (N0M0) disease. Thirteen (72%) of the tumors were Fuhrman Grade 1, while the remaining 5 (28%) were Fuhrman Grade 2. By comparison, only 60% of the clear cell RCC tumors were Grade 1 or 2. Similarly, 83% of cRCC were pT1 tumors compared to only 35% of conventional clear cell tumors. Mean tumor size for the cRCC tumors was 4.9 cm compared to 7.4 cm for conventional clear cell tumors. Cystic RCC patients had an 82% four-year disease-specific survival (DSS). Unilocular and multilocular cRCC is a distinct subtype of clear cell RCC. Its biology appears to be more favorable with regards to important prognostic factors such as metastatic presentation, Fuhrman grade, 1997 T stage, and tumor size. These findings suggest that cRCC patients may benefit from nephron sparing surgery.
10.1016/S1078-1439(03)00173-X
Surgical outcomes of robot-assisted laparoscopic partial nephrectomy for cystic renal cell carcinoma.
Journal of robotic surgery
To compare the surgical outcomes of robot-assisted partial nephrectomy (RAPN) between patients with cystic renal cell carcinoma (cRCC) and those with solid RCC (sRCC). We retrospectively analyzed 1065 patients who underwent RAPN between 2013 and 2020 for a pathological diagnosis of RCC. Patients were divided into two groups: cRCC and sRCC. cRCC was diagnosed according to the Bosniak classification system. To minimize selection bias between the two groups, patient variables (patient characteristics) and tumor factors (such as size and complexity) were adjusted using 1:1 propensity score matching. Of the 1065 patients, 94 (9%) were diagnosed with cRCC. Bosniak categories of IIF, III, and IV were noted in 4 (4.2%), 31 (33%), and 59 (63%) patients, respectively. After matching, 83 patients each were assigned to the cRCC and sRCC groups. The operation time in cRCC tended to be longer than in sRCC but not significantly different (164 vs. 150 min, P = 0.0767). Other surgical outcomes, such as change in estimated glomerular filtration rate ( - 5.2 vs. - 7.2%, P = 0.1577), perioperative complications (14.5 vs. 15.7%, P = 0.9225), estimated blood loss (62 vs. 58 mL, P = 0.5613), or negative surgical margin status (100 vs 99%, P = 0.236), were not significantly different between the two groups. During the follow-up period of about 2 years, one and two patients showed recurrence in the cRCC and sRCC groups, respectively. The surgical outcomes of RAPN were similar between cRCC and sRCC, demonstrating the feasibility of RAPN for cRCC.
10.1007/s11701-021-01292-7
Cystic renal cell carcinoma is cured by resection: a study of 24 cases with long-term followup.
Corica F A,Iczkowski K A,Cheng L,Zincke H,Blute M L,Wendel A,Sebo T J,Neumann R,Bostwick D G
The Journal of urology
PURPOSE:The true incidence and biological behavior of cystic renal cell carcinoma are not known. To our knowledge we present the largest series of patients with cystic renal cell carcinoma with long-term followup. MATERIALS AND METHODS:We reviewed the Mayo Clinic surgical pathology files of renal cell cancer cases with a cystic component resected from 1969 to 1997, and arbitrarily chose 75% tumor involvement by cysts as a cutoff for inclusion in the study. RESULTS:We identified 24 cases of clear cell renal cell carcinoma with 75% or greater involvement by cysts comprising 0.79% of 3,047 renal cell cancer cases resected at our institution between 1969 and 1997. Mean patient age was 62.7 years (range 40 to 83). A total of 11 patients (46%) underwent radical nephrectomy, 4 (17%) simple nephrectomy, 3 (12%) partial nephrectomy and 6 (25%) tumor enucleation. Mean tumor involvement by cysts was 84% (range 75 to 95) and in 11 cases (46%) involvement was 90% or greater. Cancer stage was T1 in 20 patients (83%), T2 in 1 (4.4%) and T3a in 4 (12.5%). Cancers were diploid in all but 1 case. Mean followup was 77.6 months (range 8 to 428, median 51). A total of 22 patients (92%) had no evidence of cancer and 2 died of intercurrent disease. CONCLUSIONS:Our results indicate that cystic renal cell carcinoma is uncommon and usually cured by resection, regardless of size, stage or number of cysts. These patients may benefit from nephron sparing surgery, such as partial nephrectomy.
10.1016/s0022-5347(01)61903-7
Novel, emerging and provisional renal entities: The Genitourinary Pathology Society (GUPS) update on renal neoplasia.
Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc
The Genitourinary Pathology Society (GUPS) undertook a critical review of the recent advances in renal neoplasia, particularly focusing on the newly accumulated evidence post-2016 World Health Organization (WHO) classification. In the era of evolving histo-molecular classification of renal neoplasia, morphology is still key. However, entities (or groups of entities) are increasingly characterized by specific molecular features, often associated either with recognizable, specific morphologies or constellations of morphologies and corresponding immunohistochemical profiles. The correct diagnosis has clinical implications leading to better prognosis, potential clinical management with targeted therapies, may identify hereditary or syndromic associations, which may necessitate appropriate genetic testing. We hope that this undertaking will further facilitate the identification of these entities in practice. We also hope that this update will bring more clarity regarding the evolving classification of renal neoplasia and will further reduce the category of "unclassifiable renal carcinomas/tumors". We propose three categories of novel entities: (1) "Novel entity", validated by multiple independent studies; (2) "Emerging entity", good compelling data available from at least two or more independent studies, but additional validation is needed; and (3) "Provisional entity", limited data available from one or two studies, with more work required to validate them. For some entities initially described using different names, we propose new terminologies, to facilitate their recognition and to avoid further diagnostic dilemmas. Following these criteria, we propose as novel entities: eosinophilic solid and cystic renal cell carcinoma (ESC RCC), renal cell carcinoma with fibromyomatous stroma (RCC FMS) (formerly RCC with leiomyomatous or smooth muscle stroma), and anaplastic lymphoma kinase rearrangement-associated renal cell carcinoma (ALK-RCC). Emerging entities include: eosinophilic vacuolated tumor (EVT) and thyroid-like follicular renal cell carcinoma (TLFRCC). Finally, as provisional entities, we propose low-grade oncocytic tumor (LOT), atrophic kidney-like lesion (AKLL), and biphasic hyalinizing psammomatous renal cell carcinoma (BHP RCC).
10.1038/s41379-021-00737-6
Cystic Renal Masses: Old and New Paradigms.
The Urologic clinics of North America
Cystic renal masses describe a spectrum of lesions with benign and/or malignant features. Cystic renal masses are most often identified incidentally with the Bosniak classification system stratifying their malignant potential. Solid enhancing components most often represent clear cell renal cell carcinoma yet display an indolent natural history relative to pure solid renal masses. This has led to an increased adoption of active surveillance as a management strategy in those who are poor surgical candidates. This article provides a contemporary overview of historical and emerging clinical paradigms in the diagnosis and management of this distinct clinical entity.
10.1016/j.ucl.2023.01.003
Cystic Clear Cell Renal Cell Carcinoma: A Morphological and Molecular Reappraisal.
Cancers
A wide variety of renal neoplasms can have cystic areas. These can occur for different reasons: some tumors have an intrinsic cystic architecture, while others exhibit pseudocystic degeneration of necrotic foci or they have cystically dilated renal tubules constrained by stromal neoplastic cells. Clear cell renal cell carcinoma (CCRCC), either solid or cystic, is the most frequent type of renal cancer. While pseudocysts are found in high-grade aggressive CCRCC, cystic growth is associated with low-grade indolent cases. The latter also form through a cyst-dependent molecular pathway, and they are more frequent in patients suffering from VHL disease. The differential diagnosis of multilocular cystic renal neoplasm of low malignant potential and clear cell papillary renal cell tumor can be especially hard and requires a focused macroscopical and microscopical pathological analysis. As every class of renal tumor includes cystic forms, knowledge of the criteria required for a differential diagnosis is mandatory.
10.3390/cancers15133352
Tubulocystic renal cell carcinoma: a review of literature focused on radiological findings for differential diagnosis.
Honda Yukiko,Nakamura Yuko,Goto Keisuke,Terada Hiroaki,Sentani Kazuhiro,Yasui Wataru,Sekino Yohei,Hayashi Tetsutaro,Teishima Jun,Matsubara Akio,Akagi Motonori,Fuji Tomoyo,Baba Yasutaka,Iida Makoto,Awai Kazuo
Abdominal radiology (New York)
Tubulocystic renal cell carcinoma (TC-RCC) has been classified as an independent subtype according to the 2016 World Health Organization (WHO) classification. It is a rare subtype that predominantly affects men. Although few in number, radiological imaging reports have suggested that TC-RCC is characterized by multilocular cystic lesions, which are categorized as the Bosniak classification II-IV, with signature pathological characteristics comprising numerous small cysts or a tubular structure. The Bosniak classification system facilitates patient management; however, the differentiation of cystic tumors exhibiting similar imaging findings remains impossible; in fact, the differentiation of multilocular cystic RCC, adult cystic nephroma, and mixed epithelial and stromal tumor remains challenging. This review aims to discuss TC-RCC with a focus on implications of radiological findings in the differential diagnosis of TC-RCC.
10.1007/s00261-018-1643-8
Tubulocystic renal cell carcinoma: a distinct clinicopathologic entity with a characteristic genomic profile.
Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc
Tubulocystic renal cell carcinoma, a unique tumor, was recently included as a new entity in the World Health Organization classification of renal tumors. It has variably been reported to be related to other renal cell carcinomas, including papillary renal cell carcinoma, fumarate hydratase-deficient carcinoma, and others, likely because many such carcinomas may show variable amounts of tubulocystic architecture. The published data characterizing the molecular features of these tumors are inconsistent. We studied nine "pure" tubulocystic renal cell carcinomas, as defined by International Society of Urologic Pathologists (ISUP) and World Health Organization (WHO), by targeted next-generation sequencing, and fluorescence in situ hybridization for X and Y chromosomes, to investigate if these show any unique characteristics or any overlap with known mutational/molecular profiles or copy number alterations in other subtypes of renal cell carcinoma. All nine tubulocystic carcinomas demonstrated combined losses at chromosome 9 and gains at chromosome 17, as well as, loss of chromosome Y (in 5/5). None of the tumors showed mutational profiles characteristic of other renal neoplasms, including those seen in fumarate hydratase-deficient renal cell carcinoma. Recurrent mutations in chromatin-modifying genes, KMT2C and KDM5C, were detected in two of nine tumors. Thus, tubulocystic renal cell carcinoma, if defined strictly, at the clinical and pathologic level, demonstrates genomic features distinct from other subtypes of renal cell carcinoma. These findings support the contention that tubulocystic renal cell carcinoma should be diagnosed only using strict morphological criteria and only when presenting in a "pure" form; presence of variable papillary, poorly differentiated, or other architectural patterns most likely do not belong to the category of tubulocystic renal cell carcinoma.
10.1038/s41379-018-0185-5
The 2016 WHO Classification of Tumours of the Urinary System and Male Genital Organs-Part A: Renal, Penile, and Testicular Tumours.
Moch Holger,Cubilla Antonio L,Humphrey Peter A,Reuter Victor E,Ulbright Thomas M
European urology
UNLABELLED:The fourth edition of the World Health Organization (WHO) classification of urogenital tumours (WHO "blue book"), published in 2016, contains significant revisions. These revisions were performed after consideration by a large international group of pathologists with special expertise in this area. A subgroup of these persons met at the WHO Consensus Conference in Zurich, Switzerland, in 2015 to finalize the revisions. This review summarizes the most significant differences between the newly published classification and the prior version for renal, penile, and testicular tumours. Newly recognized epithelial renal tumours are hereditary leiomyomatosis and renal cell carcinoma (RCC) syndrome-associated RCC, succinate dehydrogenase-deficient RCC, tubulocystic RCC, acquired cystic disease-associated RCC, and clear cell papillary RCC. The WHO/International Society of Urological Pathology renal tumour grading system was recommended, and the definition of renal papillary adenoma was modified. The new WHO classification of penile squamous cell carcinomas is based on the presence of human papillomavirus and defines histologic subtypes accordingly. Germ cell neoplasia in situ (GCNIS) of the testis is the WHO-recommended term for precursor lesions of invasive germ cell tumours, and testicular germ cell tumours are now separated into two fundamentally different groups: those derived from GCNIS and those unrelated to GCNIS. Spermatocytic seminoma has been designated as a spermatocytic tumour and placed within the group of non-GCNIS-related tumours in the 2016 WHO classification. PATIENT SUMMARY:The 2016 World Health Organization (WHO) classification contains new renal tumour entities. The classification of penile squamous cell carcinomas is based on the presence of human papillomavirus. Germ cell neoplasia in situ of the testis is the WHO-recommended term for precursor lesions of invasive germ cell tumours.
10.1016/j.eururo.2016.02.029
Comparison of partial nephrectomy and radical nephrectomy for cystic renal cell carcinoma: a SEER-based and retrospective study.
Scientific reports
Cystic renal cell carcinoma (cRCC) is uncommon and surgical indication remains controversial. We compared radical nephrectomy (RN) with partial nephrectomy (PN) in patients with cRCC using data from the Surveillance, Epidemiology and End Results (SEER) database and a retrospective cohort including 106 cRCC patients hospitalized in Ruijin and Renji Hospitals from 2013 to 2022. The baseline characteristics between RN and PN groups in both cohorts were adjusted by propensity score-matching (PSM). A total of 640 patients were included in the SEER cohort. Before PSM, PN group in the SEER cohort had a lower level of T stage (p < 0.001) and comprised more Caucasians (p < 0.001). After PSM, RN was associated with worse overall survival (p < 0.001) and cancer-specific survival (p = 0.006) in contrast to PN. In the Chinese cohort, 86 patients who underwent PN and 20 patients who underwent RN were finally included. The mean proportions of estimated glomerular filtration rate preserved after RN were worse than PN. Therefore, PN should be preferred in cRCC patients.
10.1038/s41598-023-34950-x
Cystic renal cell carcinoma: pathological features, survival and implications for treatment.
Bielsa O,Lloreta J,Gelabert-Mas A
British journal of urology
OBJECTIVES:To assess the incidence, clinicopathological features, prognosis and therapeutic options of cystic renal cell carcinoma (CRCC). PATIENTS AND METHODS:The clinical records and nephrectomy specimens from 206 patients with renal cell carcinoma (RCC) were reviewed after a minimum follow-up of 5 years. The mode of presentation, tumour size, growth pattern, nuclear grade, cytoplasmic appearance and pathological stage at presentation were compared with the outcome, as measured by disease-free and overall survival of the patients. RESULTS:From the 206 patients with RCC, 25 (12%) were classified as having CRCC; most of these cases (96%) occurred in male patients, as opposed to 64% in the remaining patients RCC (P = 0.0029). The clinical features at diagnosis were similar in both groups, although asthenia, anorexia and weight loss were uncommon in patients with CRCC (P = 0.045). Nuclear grade and pathological stage were usually lower in those with CRCC than in those with RCC (P = 0.0071 and P = 0.0033, respectively). Survival was significantly longer in patients with CRCC (P = 0.0342). CONCLUSIONS:CRCC is a type of RCC that is usually identified at earlier stages, has a slower growth rate, and is therefore associated with a better prognosis and longer survival than conventional RCC. The differential diagnosis between CRCC, cystic multilocular nephroma and cysts with a superimposed infectious or haemorrhagic process can be extremely difficult in imaging studies, and even in intra-operative frozen-section analysis. Because of this, and with the better prognosis of CRCC, a conservative surgical approach would be the treatment of choice whenever technically feasible.
10.1046/j.1464-410x.1998.00689.x
Cystic renal tumors: new entities and novel concepts.
Moch Holger
Advances in anatomic pathology
Cystic renal neoplasms and renal epithelial stromal tumors are diagnostically challenging and represent some novel tumor entities. In this article, clinical and pathologic features of established and novel entities are discussed. Predominantly cystic renal tumors include cystic nephroma/mixed epithelial and stromal tumor, synovial sarcoma, and multilocular cystic renal cell carcinoma. These entities are own tumor entities of the 2004 WHO classification of renal tumors. Tubulocystic carcinoma and acquired cystic disease-associated renal cell carcinoma are neoplasms with an intrinsically cystic growth pattern. Both tumor types should be included in a future WHO classification as novel entities owing to their characteristic features. Cysts and clear cell renal cell carcinoma frequently coexist within the kidneys of patients with von Hippel-Lindau disease. Sporadic clear cell renal cell carcinomas often contain cysts, usually as a minor component. Some clear cell renal cell carcinomas have prominent cysts, and multilocular cystic renal cell carcinoma is composed almost exclusively of cysts. Recent molecular findings suggest that clear cell renal cancer may develop through cyst-dependent and cyst-independent molecular pathways.
10.1097/PAP.0b013e3181d98c9d
Multilocular cystic renal cell carcinoma is a subtype of clear cell renal cell carcinoma.
Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc
Multilocular cystic renal cell carcinoma is an uncommon low grade renal cell carcinoma with unique morphologic features. Its cytogenetic characteristics have not been fully investigated. Its relationship to typical clear cell renal cell carcinoma is uncertain. We evaluated 19 cases of multilocular cystic renal cell carcinoma diagnosed by strict morphologic criteria using the 2004 WHO classification system. The control group consisted of 19 low grade (Fuhrman grades 1 or 2) clear cell renal cell carcinomas. Chromosome 3p deletion status was determined by dual color interphase fluorescence in situ hybridization analysis. Chromosome 3p deletion was identified in 17 out of 19 (89%) of the clear cell renal cell carcinoma cases and 14 out of 19 (74%) of the multilocular cystic renal cell carcinoma cases, respectively. There was no difference in the status of chromosome 3p deletion between clear cell renal cell carcinoma and multilocular cystic renal cell carcinoma (P=0.40). These results support the concept that multilocular cystic renal cell carcinoma as a subtype of clear cell renal cell carcinoma.
10.1038/modpathol.2010.78
Complex renal cysts (Bosniak ≥IIF): interobserver agreement, progression and malignancy rates.
Lucocq James,Pillai Sanjay,Oparka Richard,Nabi Ghulam
European radiology
OBJECTIVE:The objective was to assess the interobserver agreement rate, progression rates and malignancy rates in the assessment of complex renal cysts (≥ Bosniak IIF) using a population-based database. METHODS:A regional database identified 452 complex renal cysts in 415 patients between 2009 and 2019. Each patient was tracked and followed up using a unique identifier and deterministic linkage methodology. The interobserver agreement rate between radiologists was calculated using a weighted kappa statistic. Progression and malignancy rates of cysts (Bosniak ≥IIF) over the 11-year period were calculated. RESULTS:The linear-weighted kappa value was 0.69 for all complex cysts. The rate of progression and regression of Bosniak IIF cysts was 4.6% (7/151) and 3.3% (5/151), respectively. All malignant IIF cysts progressed within 16 months of diagnosis. The malignancy rate of surgically resected Bosniak III and IV cysts was 79.3% (23/29) and 84.5% (39/46), respectively. Of all malignant tumours, 73.8% and 93.7% were of low ISUP grade and low stage, respectively. CONCLUSIONS:This study further confirms that there is a good degree of agreement between radiologists in classifying complex renal masses using the Bosniak classification. The progression rate of Bosniak IIF cysts is low, but the malignancy rates of surgically resected Bosniak IIF, III and IV cysts are high. Benign cysts are frequently resected, and a very high proportion of histopathologically confirmed cancers in complex renal cysts are of low grade and stage. KEY POINTS:• There is a good degree of agreement between radiologists in classifying complex renal masses using the Bosniak classification. • The rate of progression of Bosniak IIF cysts is low, and malignant cysts progress early during surveillance. Although the malignancy rates of resected Bosniak IIF, III and IV cysts are high, the rate of benign cyst resection is significant.
10.1007/s00330-020-07186-w
Extensively cystic renal neoplasms: cystic nephroma, cystic partially differentiated nephroblastoma, multilocular cystic renal cell carcinoma, and cystic hamartoma of renal pelvis.
Eble J N,Bonsib S M
Seminars in diagnostic pathology
Predominantly cystic renal neoplasms have been the source of diagnostic confusion and controversy. In this review, the authors analyze the clinical and pathological features of four entities that consistently exhibit a diffusely cystic growth pattern, are strikingly similar in their gross appearances, and are not separable by preoperative imaging studies. Based on the literature, this review concludes that tumors in young children that have been classified as cystic nephroma and cystic partially differentiated nephroblastoma likely represent a single entity, and all should be considered highly cystic Wilms' tumors with little or no capacity for invasion or metastasis and diagnosed as cystic partially differentiated nephroblastoma. Conversely, cystic nephroma in adults has no discernible connection with Wilms' tumor or nephrogenic rests and should be considered a benign composite neoplasm of stroma and epithelium of unknown histogenesis, which may rarely become malignant with secondary development of a sarcoma. Multilocular cystic renal cell carcinoma appears to be unrelated to cystic nephroma and if the following criteria are met, it appears to be a neoplasm with an intrinsically cystic growth pattern, and no, or at most little, malignant potential: (1) an expansile mass is surrounded by a fibrous wall, (2) the interior of the tumor entirely is composed of cysts and septa with no expansile solid nodules, and (3) the septa contain aggregates of epithelial cells with clear cytoplasm. Cystic hamartoma of the renal pelvis is a rare, complex tumor composed of stroma with a prominent smooth muscle component and a variety of epithelial elements.
Cystic renal cell carcinoma.
Hartman D S,Davis C J,Johns T,Goldman S M
Urology
Cystic renal cell carcinoma includes any malignant neoplasm of renal tubular epithelium which presents as a fluid-filled mass. Approximately 15 per cent of cases of renal cell carcinoma will be cystic on radiologic and pathologic examination. The clinical features of cystic renal cell carcinoma are similar to those which are solid. The radiographic and pathologic findings of cystic renal cell carcinoma are often more confusing and less specific than the findings of renal cell carcinoma which are predominantly solid. There are four basic pathologic mechanisms resulting in cystic renal cell carcinoma: intrinsic multiloculated growth; intrinsic unilocular growth (cystadenocarcinoma); cystic necrosis; and origin from the epithelial lining of a preexisting simple cyst. There are three basic radiologic patterns of cystic renal cell carcinoma: unilocular cystic mass, multiloculated cystic mass, and discrete mural nodule in a cystic mass. Cystic renal cell carcinoma is often extremely difficult to differentiate from non-neoplastic, benign neoplastic, and other malignant neoplastic masses utilizing radiologic studies alone. This review presents the clinical, pathologic, and radiographic features of cystic renal cell carcinoma and discusses its radiologic differential diagnosis.
10.1016/0090-4295(86)90109-3
Cystic Renal Cell Carcinoma: A Report on Outcomes of Surgery and Active Surveillance in Patients Retrospectively Identified on Pretreatment Imaging.
Kashan Mahyar,Ghanaat Mazyar,Hötker Andreas M,Duzgol Cihan,Sanchez Alejandro,DiNatale Renzo G,Blum Kyle A,Becerra Maria F,Manley Brandon J,Casuscelli Jozefina,Chiok Michael,Coleman Jonathan A,Russo Paul,Tickoo Satish K,Akin Oguz,Hakimi A Ari
The Journal of urology
PURPOSE:We evaluated the outcomes of surgical intervention and active surveillance in patients diagnosed with cystic renal cell carcinoma at our hypothesized radiological cutoff of greater than 50% cystic. MATERIALS AND METHODS:We identified all 430 patients with a pathologically confirmed cystic renal mass that fit our criteria from 2000 to 2015. The 292 patients with a lack of computerized tomography, tumors less than 50% cystic on imaging, multifocal tumors and prior renal cell carcinoma were excluded from study. Patients were stratified into benign or malignant subgroups, and radiological, clinicopathological and oncologic features were determined. Univariate and multivariate associations between clinicoradiological parameters in each group were analyzed. We similarly reviewed the records of a separate cohort of patients treated with active surveillance for cystic renal cell carcinoma. RESULTS:Of the 138 identified cases of cystic renal cell carcinoma 102 (73.9%) were renal cell carcinoma and 36 (26.1%) were benign masses. Of the tumors 77.5% were Fuhrman grade 1-2, 83.4% were stage pT2 or less and 65.9% showed clear cell histology. On univariate analysis male gender, a solid component and increasing Bosniak classification were significant for malignancy. In a separate cohort we identified 38 patients on active surveillance. The growth rate was 1.0 mm per year overall and 2.3 mm per year for the solid component. At a median followup of more than 4 years in all cohorts there was no evidence of recurrence or metastasis of cystic renal cell carcinoma. CONCLUSIONS:Patients with unifocal cystic renal cell carcinoma evaluated using a standardized radiological threshold of greater than 50% cystic had an excellent prognosis on active surveillance and after surgical resection.
10.1016/j.juro.2018.02.3087
Bosniak Classification version 2019: validation and comparison to original classification in pathologically confirmed cystic masses.
Yan Jin Hui,Chan Jason,Osman Heba,Munir Javeria,Alrasheed Sumaya,Flood Trevor A,Schieda Nicola
European radiology
OBJECTIVE:To evaluate Bosniak Classification v2019 definitions in pathologically confirmed cystic renal masses. MATERIALS AND METHODS:Seventy-three cystic (≤ 25% solid) masses with histological confirmation (57 malignant, 16 benign) imaged by CT (N = 28) or CT+MRI (N = 56) between 2009 and 2019 were independently evaluated by three blinded radiologists using Bosniak v2019 and original classifications. Discrepancies were resolved by consensus with a fourth blinded radiologist. Overall class and v2019 features were compared to pathology. RESULTS:Inter-observer agreement was slightly improved comparing v2019 to Original Bosniak Classification (kappa = 0.26-0.47 versus 0.24-0.34 respectively). v2019 proportion of IIF and III masses (20.5% [15/73, 95% confidence interval (CI) 12.0-31.6%], 38.6% [28/73, 95% CI 27.2-50.5%]) differed from the original classification (6.8% [5/73, 95% CI 2.3-15.3%], 61.6% [45/73, 95% CI 49.5-72.8%]) with overlapping proportion of malignancy in each class. Mean septa number (7 ± 4 [range 1-10]) was not associated with malignancy (p = 0.89). Mean wall and septa thicknesses were 3 ± 3 (1-14) and 3 ± 2 (1-10) mm and higher in malignancies (p = 0.03 and 0.20 respectively). Areas under the receiver-operator-characteristic curve for wall and septa thickness were 0.66 (95% CI 0.54-0.79) and 0.61 (95% CI 0.45-0.78) with an optimal cut point of ≥ 3 mm (sensitivity 33.3%, specificity 86.7% and sensitivity 53%, specificity 73% respectively). Proportion of malignancy occurring in masses with the v2019 features "irregularity" (76.9% [10/13], 95% CI 46.2-94.9%) and "nodule" (89.7% [26/29], 95% CI 72.7-97.8%) overlapped. Angle of "nodule" (p = 0.27) was not associated with malignancy. CONCLUSION:Bosniak v2019 definitions for wall/septa thickness and protrusions are associated with malignancy. Overall, Bosniak v2019 categorizes a higher proportion of malignant masses in Class IIF with slight improvement in inter-observer agreement. KEY POINTS:• Considering Bosniak v2019 Class IIF cystic masses with many (≥ 4) smooth and thin septa, there was no association between the number of septa and malignancy (p = 0.89) in this study. • Increased cyst wall and septa thickness are associated with malignancy and a lower threshold of ≥ 3 mm maximized overall diagnostic accuracy compared to ≥ 4 mm threshold proposed for Bosniak v2019 Class 3. • An overlapping proportion of malignant masses is noted in Bosniak v2019 Class 3 masses with "irregularity" (76.9% [10/13], 95% CI 46.2-94.9%) compared to Bosniak v2019 Class 4 masses with "nodule" (89.7% [26/29], 95% CI 72.7-97.8%).
10.1007/s00330-021-08006-5
Towards a new WHO classification of renal cell tumor: what the clinician needs to know-a narrative review.
Translational andrology and urology
In 1952, renal cell carcinomas had been divided into 2 categories-clear cell or granular cell-depending upon their cytoplasmic staining characteristics. In the following years, the inventory of renal epithelial tumors has expanded by the addition of tumors named by their architectural pattern (i.e., papillary RCC, tubulocystic RCC), anatomic location (i.e., collecting duct carcinoma, renal medullary carcinoma), associated diseases (i.e., acquired cystic disease-associated RCCs). With the extensive application of molecular diagnostic techniques, it becomes possible to detect genetic distinctions between various types of renal neoplasm and discover new entities, otherwise misdiagnosed or diagnosed as unclassified RCC. Some tumors such as ALK rearrangement-associated RCC, MiT family translocation renal carcinomas, SDH-deficient renal cancer or FH-deficient RCC, are defined by their molecular characteristics. The most recent World Health Organization (WHO) classification of renal neoplasms account for more than 50 entities and provisional entities. New entities might be included in the upcoming WHO classification. The aim of this review is to summarise and discuss the newly acquired data and evidence on the clinical, pathological, molecular features and on the prognosis of new RCC entities, which will hopefully increase the awareness and the acceptance of these entities among clinicians and improve prognostication for individual patients.
10.21037/tau-20-1150
Kidney pathology: current classification of renal cell carcinoma.
Current urology reports
This report discusses the new cytogenetic classification of renal cell carcinoma (RCC) and its biological and clinical significance. It describes the four major types (clear cell, chromophil, chromophobe, and collecting duct) as well as rarer entities, such as small cell carcinoma, cystic RCC, rhabdoid variant of RCC, and unclassified RCC. Sarcomatoid carcinomas are a diverse group representing high-grade transformation of the other types. In addition to a description of the pathologic findings, there is a discussion of tumor markers and prognostic indicators. The clinical significance of the classification is discussed, with reference to recent reports.
10.1007/s11934-002-0007-6
Acquired Cystic Disease-Associated Renal Cell Carcinoma: A Systematic Review and Meta-analysis.
Clinical genitourinary cancer
Acquired cystic disease-associated renal cell carcinoma (ACD-RCC) is a common subtype of renal cell carcinoma (RCC) in end-stage renal disease (ESRD) patients. The current systematic review and meta-analysis was performed to evaluate the clinicopathological, and genetic characteristics of patients with ACD-RCC. A systematic search on three electronic databases including the Pubmed, Scopus, and Web of Science databases were performed until December 31, 2022. A meta-analysis was performed following the PRISMA 2020 Guidelines. Of 888 identified articles, full-text screening in 69 articles, there were 26 articles analyzed, with a total of 2314 tumors in 2199 patients, including 418 ACD-RCC tumors in 363 patients, 1340 clear cell RCC (ccRCC) tumors, 308 papillary RCC (pRCC) tumors. Most ACD-RCC patients were male (80.2%). All the ACD-RCC patients underwent prior dialysis with 148.2 months of mean dialysis duration. There were 8.7%, 3.4%, and 5.8% tumors at the T3-4 stage, N1 stage, and M1 stage, respectively. The mean overall survival of ACD-RCC patients was 39.6 months (95% CI, 26.6-52.5). Compared to ccRCC and pRCC, ACD-RCC patients had a longer duration of dialysis (MD: 103.5 and 31.77 months, respectively; 95% CI: [75.48; 131.53] and [0.95; 62.58], respectively), and a higher rate of multifocal tumors (MD: 3.46 and 2.45 tumors, respectively; 95% CI [1.71; 6.98] and [1.26; 4.79], respectively). Regarding genetic characteristics, chromosomes 3 and 16 were the 2 most frequent chromosomal aberrations. The missense mutation in KMT2C (25%) and TSC2 (18.75%) were the 2 most common gene mutations in ACD-RCC. In conclusion, the ACD-RCC subtype exhibited several distinct clinicopathological and genetic characteristics compared to others RCC subtypes. Further researchs are needed to assess the survival outcome and the genetic characteristics of this subtype.
10.1016/j.clgc.2024.02.001
Update on MRI of Cystic Renal Masses Including Bosniak Version 2019.
Krishna Satheesh,Schieda Nicola,Pedrosa Ivan,Hindman Nicole,Baroni Ronaldo H,Silverman Stuart G,Davenport Matthew S
Journal of magnetic resonance imaging : JMRI
Incidental cystic renal masses are common, usually benign, and almost always indolent. Since 1986, the Bosniak classification has been used to express the risk of malignancy in a cystic renal mass detected at imaging. Historically, magnetic resonance imaging (MRI) was not included in that classification. The proposed Bosniak v.2019 update has formally incorporated MRI, included definitions of imaging terms designed to improve interobserver agreement and specificity for malignancy, and incorporated a variety of masses that were incompletely defined or not included in the original classification. For example, at unenhanced MRI, homogeneous masses markedly hyperintense at T -weighted imaging (similar to cerebrospinal fluid) and homogeneous masses markedly hyperintense at fat suppressed T -weighted imaging (approximately ≥2.5 times more intense than adjacent renal parenchyma) are classified as Bosniak II and may be safely ignored, even when they have not been imaged with a complete renal mass MRI protocol. MRI has specific advantages and is recommended to evaluate masses that at computed tomography (CT) 1) have abundant thick or nodular calcifications; 2) are homogeneous, hyperattenuating, ≥3 cm, and nonenhancing; or 3) are heterogeneous and nonenhancing. Although MRI is generally excellent for characterizing cystic renal masses, there are unique weaknesses of MRI that bear consideration. These details and others related to MRI of cystic renal masses are described in this review, with an emphasis on Bosniak v.2019. A website (https://bosniak-calculator.herokuapp.com/) and mobile phone apps named "Bosniak Calculator" have been developed for ease of assignment of Bosniak classes. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY STAGE: 3.
10.1002/jmri.27364
Clinics in diagnostic imaging (135). Cystic renal cell carcinoma.
Pojchamarnwiputh S,Muttarak M,Sriplakich S
Singapore medical journal
A 45-year-old man presented with right flank pain and haematuria for one month. Computed tomography showed a large, well-circumscribed exophytic complex cystic mass with enhanced, irregular thickened walls arising from the upper pole of the right kidney, which was associated with bilateral renal stones. Partial right nephrectomy with removal of the right renal stones was performed. Histopathology revealed papillary cell carcinoma confined to the kidney. The patient made good postoperative recovery. The Bosniak classification system of renal cystic lesions and cystic renal cell carcinoma are discussed. Various cases of renal cystic lesions and cystic renal cell carcinoma are shown.
The 2022 World Health Organization Classification of Tumours of the Urinary System and Male Genital Organs-Part A: Renal, Penile, and Testicular Tumours.
European urology
The fifth edition of the World Health Organization (WHO) classification of urogenital tumours (WHO "Blue Book"), published in 2022, contains significant revisions. This review summarises the most relevant changes for renal, penile, and testicular tumours. In keeping with other volumes in the fifth edition series, the WHO classification of urogenital tumours follows a hierarchical classification and lists tumours by site, category, family, and type. The section "essential and desirable diagnostic criteria" included in the WHO fifth edition represents morphologic diagnostic criteria, combined with immunohistochemistry and relevant molecular tests. The global introduction of massive parallel sequencing will result in a diagnostic shift from morphology to molecular analyses. Therefore, a molecular-driven renal tumour classification has been introduced, taking recent discoveries in renal tumour genomics into account. Such novel molecularly defined epithelial renal tumours include SMARCB1-deficient medullary renal cell carcinoma (RCC), TFEB-altered RCC, Alk-rearranged RCC, and ELOC-mutated RCC. Eosinophilic solid and cystic RCC is a novel morphologically defined RCC entity. The diverse morphologic patterns of penile squamous cell carcinomas are grouped as human papillomavirus (HPV) associated and HPV independent, and there is an attempt to simplify the morphologic classification. A new chapter with tumours of the scrotum has been introduced. The main nomenclature of testicular tumours is retained, including the use of the term "germ cell neoplasia in situ" (GCNIS) for the preneoplastic lesion of most germ cell tumours and division from those not derived from GCNIS. Nomenclature changes include replacement of the term "primitive neuroectodermal tumour" by "embryonic neuroectodermal tumour" to separate these tumours clearly from Ewing sarcoma. The term "carcinoid" has been changed to "neuroendocrine tumour", with most examples in the testis now classified as "prepubertal type testicular neuroendocrine tumour".
10.1016/j.eururo.2022.06.016
Differential diagnosis of complex cystic renal mass using multiphase computerized tomography.
Song Cheryn,Min Gyeong Eun,Song Kanghyon,Kim Jeong Kon,Hong Bumsik,Kim Choung-Soo,Ahn Hanjong
The Journal of urology
PURPOSE:We evaluated the additional usefulness of multiphase computerized tomography for improving the differential diagnosis of cystic renal masses by the Bosniak classification. MATERIALS AND METHODS:We reviewed the records of 104 patients with Bosniak class II (29 or 27.8%), III (38 or 36.5%) and IV (37 or 35.7%) cystic renal masses managed surgically between 1997 and 2007. On preoperative multiphase computerized tomography enhancement differences in HU between the precontrast and corticomedullary phases were measured at the highest enhancement area to correlate with pathological findings. RESULTS:Renal cell carcinoma was diagnosed in 56 patients (53.8%). Of the tumors 35 (62.5%) showed clear cell histology. According to Bosniak class 3 (11.5%), 21 (55.2%) and 32 (86.4%) class II to IV lesions, respectively, were diagnosed as renal cell carcinoma. For renal cell carcinoma and benign cysts mean HU at the precontrast phase was similar (31.5 and 32.4 HU, respectively), while renal cell carcinoma showed a significantly higher measurement at the corticomedullary phase (112.9 vs 59.8 HU, p <0.0001). To differentiate renal cell carcinoma a corticomedullary phase minus precontrast phase value of greater than 42 HU was predictive with 97.1% sensitivity and 85.7% specificity (area under the ROC curve 0.966). In a multiple regression model the corticomedullary phase minus precontrast phase value and the Bosniak classification independently determined malignant pathological findings (corticomedullary phase minus precontrast phase greater than 42 HU HR 31.541, 95% CI 8.320-119.563 and Bosniak class HR 5.545, 95% CI 2.153-14.279, each p <0.0001). CONCLUSIONS:In cases of complex cystic renal masses diagnostic accuracy can be improved to differentiate renal cell carcinoma by combining Bosniak class and enhancement differences measured on multiphase computerized tomography between precontrast and maximal enhancement phases. This would help determine the need for and the method of surgical treatment.
10.1016/j.juro.2009.01.111
Multilocular cystic renal cell carcinoma: a rare entity with review of literature.
Wahal Shailja Puri,Mardi Kavita
Journal of laboratory physicians
Multilocular cystic renal cell carcinoma (MCRCC) represents a rare variant of clear cell renal cell carcinoma (RCC). MCRCC has been recognized as a separate subtype of RCC in the 2004 World Health Organization (WHO) classification of adult renal tumors. MCRCC is diagnosed on the basis of strict histological criteria according to 2004 WHO classification. The chief differentials diagnosis to be considered include cystic nephroma, cystic clear cell carcinoma, clear cell papillary renal cell carcinoma and tubulocystic carcinoma. Only few cases of MCRCC are reported in literature. This case is being highlighted for its rarity and so as to avoid a misdiagnosis as conventional RCC.
10.4103/0974-2727.129093
What's new in the WHO 2022 classification of kidney tumours?
Pathologica
The World Health Organization (WHO) 2022 classification of urinary and male genital tumours (5th edition) has significantly improved our understanding of the morphologic, immunohistochemical, and molecular characteristics of renal tumours. The aim of this review is to outline the most important changes and diagnostic updates in the WHO 2022 classification of kidney tumours. A major change in this edition is the grouping of renal tumours into broader categories that include "", "", "", as well as adding two categories of "" and "". Novel entities included in the WHO 2022 classification are eosinophilic solid and cystic renal cell carcinoma (ESC RCC), anaplastic lymphoma kinase (-rearranged RCC and (formerly )-mutated RCC. The category of "" includes a group of diverse, unrelated renal tumours that do not fit into other categories. The group of "" reflects recent discoveries in the renal tumour genomics. These molecularly-defined renal entities demonstrate a set of morphologic features reflecting genotype-phenotype relationships. Final diagnosis of such entities rests on phenotypic and immunohistochemical (IHC) correlation, usually associated with IHC surrogate makers that reflect specific genetic abnormalities.
10.32074/1591-951X-818
Comparison of survival between unilocular cystic and purely solid renal cell carcinoma.
Scientific reports
To evaluate clinicopathological features and survival outcomes of unilocular cystic renal cell carcinoma (ucRCC) compared with purely solid renal cell carcinoma (sRCC), and to evaluate the oncologic aggressiveness of ucRCC. The relevant data of 957 patients with sporadic unilateral renal cell carcinoma (RCC) underwent surgical treatment in 2 institutions from Jan 2014 to Oct 2018 were obtained. We excluded multilocular cystic renal neoplasm of low malignant potential (MCRNLMP), RCC with multilocular cysts and necrotic RCC. 74 ucRCCs were identified by pathology reports. We performed propensity score matching (PSM) and eventually selected 144 sRCCs. The clinicopathological features and survival outcomes were compared properly. After PSM, age, BMI, Charlson Comorbidity Index, and postoperative Chronic Kidney Disease grade were not significantly different. Both overall survival and progression-free survival of ucRCC were significantly better than sRCC by the log-rank test. Twenty-five cases of sRCCs were in the pT3 or pT4 stage, while no pT3 or pT4 tumors were found in ucRCCs. Fuhrman grade and lymphatic metastasis were found to be significant prognostic factors for the overall survival of ucRCC. Unilocular cystic RCC has a lower Fuhrman grade and pathological stage and a better prognosis compared with solid RCC. Patients with ucRCC still probably have lymphatic metastasis at surgery and may have postoperative metastasis, which is different from MCRNLMP. We recommend that the diagnosis of ucRCC should be reflected in pathology report. Different subtype of cystic RCC should be taken into consideration in counseling and management.
10.1038/s41598-022-16856-2
A case of pyelocalyceal diverticulum urothelial carcinoma that was difficult to distinguish from cystic renal cell carcinoma preoperatively.
IJU case reports
INTRODUCTION:Pyelocalyceal diverticulum is a rare disease sometimes difficult to distinguish from cysts. We report a case of urothelial carcinoma originating from a pyelocalyceal diverticulum, difficult to distinguish from cystic renal cell carcinoma preoperatively. CASE PRESENTATION:A 51-year-old Japanese man complained of gross hematuria. Computed tomography revealed a solid mass in one of the many cystic lesions in the left kidney. He was diagnosed with left cystic renal cell carcinoma and underwent retroperitoneal laparoscopic nephrectomy. Pathological examination revealed high-grade invasive urothelial carcinoma arising within the renal pyelocalyceal diverticulum. The definitive diagnosis was high-grade invasive urothelial carcinoma (pT3). In retrospect, the retrograde pyelography findings indicated the cyst and urinary tract connection. Residual ureterectomy and adjuvant chemotherapy were later performed. The patient has since been recurrence-free. CONCLUSION:Whether cystic renal cell carcinoma is suspected on imaging, pyelocalyceal diverticulum should be considered a differential diagnosis, though unlikely to be encountered in daily practice.
10.1002/iju5.12361
Implication of cystic fluid cytology of renal cell carcinoma on surgical practice.
BMC urology
OBJECTIVES:To evaluate the incidence of positive cystic fluid cytology and its risk factors in cystic renal cell carcinoma (RCC) addressing its implication on the current surgical practice. METHODS:All clinically diagnosed Bosniak III, IV cystic renal masses from March 2019 to August 2022 were studied prospectively. Database of patients' demographics and cystic tumor characteristics were recorded. Partial or radical nephrectomies were performed by either laparoscopic or robotic approach. Cystic fluid was collected right after specimen retrieval in the surgical field and examined by pathologist. Cytology results were compared to the demographic, perioperative variables using univariate and multivariate analysis. RESULTS:A total of 70 patients of histologically confirmed cystic RCC were included. Sixty seven patients underwent radical nephrectomy with laparoscopic or robotic approaches, while 3 patients underwent radical nephrectomy. There was no intraoperative cystic rupture or fluid spillage. Positive cystic fluid cytology findings were identified in 34 (48.6%) patients, while negative cystic fluid cytology were identified in 36 (51.4%) cases. Definite malignant cells were observed in 28 patients while the other six patients showed highly suspicious atypical cells. Histologically, 24 (70.8%) patients were proven clear cell RCC and 25 (73%) showed Fuhrman grade 1 or 2 in final histologic review in positive group. Univariate and multivariate regression analysis between positive and negative cytology groups showed that the presence of the malignant cells in cystic fluid was significantly associated with patients' age (> 55 years) and Bosniak grade of cystic tumor (p < 0.05). CONCLUSIONS:Definite malignant cells in cystic fluid cytology were observed through our study. Additionally, patients' age (> 55 years) and Bosniak grade were the significant risk factors of positive cytology in cystic RCC. Therefore, necessity of meticulous manipulation of cystic renal tumors, despite their clinical features, should not be underemphasized to avoid the least possible tumor cell seeding in case of cystic rupture when operating such high risk of positive cytology.
10.1186/s12894-022-01144-y
Multilocular Cystic Renal Cell Carcinoma or Cystic Nephroma?
González-Serrano Adolfo,Cortez-Betancourt Roberto,Alías-Melgar Alejandro,Botello-Gómez Pedro Jair,Ramírez-Garduño Emilio,Trujillo-Vázquez Eric Iván,Torres-Santos Yosimart,Mata-Martínez José Antonio,Carreño-de la Rosa Fernando
Case reports in urology
The incidence of Multilocular cystic renal cell carcinoma (MCRCC) in literature is very low and confounding MCRCC with cystic nephroma (CN) is even more unusual. The aim of this report is to present a case of MCRCC and emphasize the importance of the preoperative radiologic evaluation and immunohistochemical staining confirmation to obtain an accurate diagnosis. A 73-year-old woman presented with a history of 4-month right flank pain. CT showed a Bosniak type III renal mass. After laparoscopic partial nephrectomy the initial report was cystic nephroma. Immunohistochemical staining was performed being positive for Epithelial Membrane Antigen thus changing the diagnosis to MCRCC. Multilocular cystic renal cell carcinoma cannot reliably be distinguished from cystic nephroma neither by physical examination nor by radiologic evaluation; immunohistochemical staining assay is useful to differentiate between these conditions allowing an accurate diagnosis and proper follow-up.
10.1155/2016/5304324
The true malignancy risk of Bosniak III cystic renal lesions: Active surveillance or surgical resection?
Canadian Urological Association journal = Journal de l'Association des urologues du Canada
INTRODUCTION:We sought to evaluate the pathological results of renal masses in comparison with Bosniak III renal cystic lesions to determine the actual malignancy risk. METHODS:A retrospective review of Bosniak III renal lesions identified by computed tomography (CT) or magnetic resonance imaging (MRI) were collected from our patients between August 1, 2013 and December 31, 2015 who underwent surgical excision. TNM stage, histology, Fuhrman grade, and maximum lesion size data was collected. Lesion size relationship with prevalence of malignancy was completed by two-tailed t-test, using the homogeneity hypothesis between malignant and benign groups. RESULTS:Fifteen of 25 (60%) of Bosniak III lesions were determined to be malignant. All malignant lesions were classified as either Fuhrman grade 1 or 2 with no evidence of progression to Bosniak IV. Average size of malignant lesions was smaller than those of benign pathology (3.52±1.99 cm vs. 5.66±2.53 cm; p=0.041). Smaller lesions (size <4 cm) were more likely to be malignant than lesions of a larger size (p=0.047). CONCLUSIONS:The malignancy risk of Bosniak III renal lesions was 60% in our study. All Bosniak III lesions were of low Fuhrman grade with no evidence of progression. No patient in this study developed metastatic disease within the three-year followup period. Smaller (<4 cm) Bosniak III cysts were more likely to be malignant and lesion size should be taken into consideration when considering management of complex cysts. Active surveillance may be a reasonable option for Bosniak III cystic lesions, regardless of overall size, based upon their universal low grade and no patient developing metastatic disease.
10.5489/cuaj.4960
Diagnostic value and clinical significance of ultrasound combined with CT in cystic renal cell carcinoma.
Sun Minghui,Wang Chao,Jiang Fei,Fang Xiuhong,Guo Bingcheng
Oncology letters
This study investigated the value and clinical significance of ultrasound combined with CT in the diagnosis of cystic renal cell carcinoma. A total of 85 patients with cystic renal cell carcinoma, who were admitted to the Oncology Department of Yantai Yuhuangding Hospital Affiliated to Qingdao University from December 2015 to April 2017, were selected as the study group, and 70 patients with benign renal cyst, who were examined in Yantai Yuhuangding Hospital Affiliated to Qingdao University, were selected as the benign group. The patients in the two groups were examined by ultrasound and CT. The diagnostic value of ultrasound, CT, and ultrasound combined with CT in cystic renal cell carcinoma was analyzed. The sensitivity of ultrasound combined with CT was significantly higher than that of CT and ultrasound (P<0.05). The specificity and diagnostic coincidence rate of ultrasound combined with CT were significantly higher than those of CT (P<0.05). For unicapsular kidney cancer, there was no significant difference among ultrasound, CT and ultrasound combined with CT in the diagnosis of septum and wall nodule (P>0.05). For polycystic kidney cancer, there was no significant difference among ultrasound, CT and ultrasound combined with CT in the diagnosis of the presence or absence of septum (P>0.05). Ultrasound was significantly better than CT in cyst wall confounding (P<0.05). Ultrasound combined with CT was significantly better than ultrasound in calcification and blood supply of tumors (P<0.05). In conclusion, the accuracy of ultrasound combined with CT is higher than that of ultrasound or that of CT in the diagnosis of cystic renal cell carcinoma, which can be beneficial in accurately carrying out clinical diagnosis, reduce the incidence of missed diagnosis and misdiagnosis caused by a single diagnosis and treatment. Ultrasound combined with CT is good for clinical screening and can guide clinical symptomatic treatment, which is worthy of generalizing in clinic.
10.3892/ol.2019.10422
Multimodality Assessment of Cystic Renal Masses.
Withey Samuel Joseph,Verma Hema,Prezzi Davide
Seminars in ultrasound, CT, and MR
Renal cysts are a common imaging finding, often incidental. Ultrasound, CT and MRI are the main modalities responsible for renal cyst detection and characterization. These modalities often play a complementary role in modern radiological practice, each of them with strengths and limitations. In view of a recently proposed 'multimodality' update to the historical Bosniak classification, this article provides a general overview of the current imaging approach to renal cysts, and outlines some of the diverse pathologic entities responsible for renal cyst formation.
10.1053/j.sult.2020.05.001
CT and MRI findings of cystic renal cell carcinoma: comparison with cystic collecting duct carcinoma.
Zhu Qingqiang,Ling Jun,Ye Jing,Zhu Wenrong,Wu Jingtao,Chen Wenxin
Cancer imaging : the official publication of the International Cancer Imaging Society
BACKGROUND:Cystic renal cell carcinoma (CRCC) and cystic collecting duct carcinoma (CCDC) share similar oncogeni and some imaging findings. The aim of this study was to characterize the clinical and CT imagings features of CRCC and CCDC. METHODS:Thirty-three patients with CRCC and thirteen patients with CCDC with pathologically proven were retrospectively studied. Tumor characteristics were assessed. RESULTS:On CT imaging, 33 patients(100 %) with CRCC and 13 patients(100 %) with CCDC, tumors calcifications (8 vs. 9, P < 0.0001), had a clear boundary (capsule sign, 30 vs. 2, P < 0.0001), infiltrative appearance (1 vs. 13, P < 0.0001), exogenous appearance (29 vs. 3, P < 0.0001), invaded the renal pelvis or ureter (1 vs. 10, P < 0.0001), hemorrhage (1 vs. 10, P < 0.0001), had retroperitoneal lymph node or distant metastasis (2 vs. 10, P < 0.0001), thickened enhancing internal septations (31 vs. 2, P < 0.0001), and mural soft-tissue nodules (21 vs. 1, P < 0.0001). On MR imaging,13 patients(39 %) with CRCC and 4 patients(31 %) with CCDC, all CRCCs appeared hypointense on T1-weighted images and hyperintense on T2-weighted images, however, all CCDCs appeared hypointense on T1-weighted images and hypointense on T2-weighted images(P < 0.0001). 33 patients with CRCC, they were all alive from3 years to 10 years follow-up, however, 13 patients with CCDC, of which 11 patients were able to be followed up, and 9 patients expired within 5 years of the initial diagnosis and the others are currently still alive. CONCLUSIONS:Distinguishing features of CRCC and CCDC included calcifications, capsule signs, infiltrative appearance, metastasis, internal septations, mural nodules and signal on CT or MR images. These imaging features may help in differentiating the two renal tumor types.
10.1186/s40644-021-00419-1
Bosniak Classification of Cystic Renal Masses, Version 2019: An Update Proposal and Needs Assessment.
Silverman Stuart G,Pedrosa Ivan,Ellis James H,Hindman Nicole M,Schieda Nicola,Smith Andrew D,Remer Erick M,Shinagare Atul B,Curci Nicole E,Raman Steven S,Wells Shane A,Kaffenberger Samuel D,Wang Zhen J,Chandarana Hersh,Davenport Matthew S
Radiology
Cystic renal cell carcinoma (RCC) is almost certainly overdiagnosed and overtreated. Efforts to diagnose and treat RCC at a curable stage result in many benign neoplasms and indolent cancers being resected without clear benefit. This is especially true for cystic masses, which compared with solid masses are more likely to be benign and, when malignant, less aggressive. For more than 30 years, the Bosniak classification has been used to stratify the risk of malignancy in cystic renal masses. Although it is widely used and still effective, the classification does not formally incorporate masses identified at MRI or US or masses that are incompletely characterized but are highly likely to be benign, and it is affected by interreader variability and variable reported malignancy rates. The Bosniak classification system cannot fully differentiate aggressive from indolent cancers and results in many benign masses being resected. This proposed update to the Bosniak classification addresses some of these shortcomings. The primary modifications incorporate MRI, establish definitions for previously vague imaging terms, and enable a greater proportion of masses to enter lower-risk classes. Although the update will require validation, it aims to expand the number of cystic masses to which the Bosniak classification can be applied while improving its precision and accuracy for the likelihood of cancer in each class.
10.1148/radiol.2019182646
Bosniak Classification Version 2019 of Cystic Renal Masses Assessed With MRI.
Tse Justin R,Shen Jody,Yoon Luke,Kamaya Aya
AJR. American journal of roentgenology
The purpose of this study was to determine how use of Bosniak classification version 2019 affects categorization and overall accuracy of MRI evaluation of cystic renal masses with tissue pathologic analysis as the reference standard. MR images of 50 consecutively registered patients with tissue pathologic results from 2005 to 2019 were retrospectively reviewed by two abdominal radiologists. Each radiologist independently assigned a category based on the original and Bosniak classification version 2019 systems. Interreader agreements (kappa statistic) for both were calculated, and consensus reading was performed. Tissue pathologic analysis was used as the reference standard to determine whether a lesion was benign or renal cell carcinoma. Fifty-nine cystic renal masses were characterized as 38 renal cell carcinomas and 21 benign lesions on the basis of the results of tissue pathologic analysis. By consensus, according to the original Bosniak criteria, the renal masses were classified into three category I, five category II, four category IIF, 25 category III, and 22 category IV lesions. By consensus, according to the version 2019 criteria, the renal masses were classified into three category I, two category II, 12 category IIF, 18 category III, and 24 category IV lesions. Overall sensitivity and specificity for identifying renal cell carcinoma were 95% and 81%, respectively, with the original classification system and 100% and 86%, respectively, with version 2019. Weighted interreader agreement was moderate for both the original system (κ = 0.57) and version 2019 (κ = 0.55). Use of Bosniak classification version 2019 system improves sensitivity and specificity for malignancy among cystic renal masses characterized with MRI. Most lesions that changed categories were reclassified as Bosniak category IIF.
10.2214/AJR.19.22740