Geert J.L.H. van Leenders

Five years after the last prostatic carcinoma grading consensus conference of the International Society of Urological Pathology (ISUP), accrual of new data and modification of clinical practice require an update of current pathologic grading guidelines. This manuscript summarizes the proceedings of the ISUP consensus meeting for grading of prostatic carcinoma held in September 2019, in Nice, France. Topics brought to consensus included the following: (1) approaches to reporting of Gleason patterns 4 and 5 quantities, and minor/tertiary patterns, (2) an agreement to report the presence of invasive cribriform carcinoma, (3) an agreement to incorporate intraductal carcinoma into grading, and (4) individual versus aggregate grading of systematic and multiparametric magnetic resonance imaging-targeted biopsies. Finally, developments in the field of artificial intelligence in the grading of prostatic carcinoma and future research perspectives were discussed.

PURPOSE: To evaluate which parameters of dynamic magnetic resonance (MR) imaging and T2 relaxation rate would result in optimal discrimination of prostatic carcinoma from normal peripheral zone (PZ) and central gland (CG) tissues and to correlate these parameters with tumor stage, Gleason score, patient age, and tumor markers. MATERIALS AND METHODS: Of 58 patients with prostatic carcinoma, 36 were included for analysis. Patients underwent MR imaging at 1.5 T with an endorectal-pelvic phased-array coil and subsequently underwent prostatectomy. A T2-weighted turbo spin-echo sequence, an intermediate-weighted sequence, and a fast T1-weighted gradient-echo sequence (seven sections in 2.03 seconds) during bolus injection of 0.1 mmol gadopentetate dimeglumine per kilogram of body weight were performed. Contrast agent concentration-time curves were obtained for prostatic carcinoma and normal PZ and CG tissue by using whole-mount sections to guide placement of regions of interest. Onset time, time to peak, peak enhancement, relative peak enhancement, washout, and T2 relaxation rates were calculated. Multivariate receiver operating characteristic analysis was performed with and without relative peak enhancement. RESULTS: Results of multivariate receiver operating characteristic analysis showed that relative peak enhancement demonstrated the highest area under the receiver operating characteristic curve (AUC) in the PZ and the CG (AUC = 0.93, 0.82). Results of multivariate analysis without relative peak enhancement showed that relative peak enhancement in the PZ and washout in the CG demonstrated the highest AUC (AUC = 0.9, 0.81). Pearson correlation coefficients between the dynamic parameters or T2 relaxation rates in carcinoma and the tumor stage, Gleason score, patient age, and tumor markers ranged between 0.02 and 0.44. CONCLUSION: The optimal parameter for discrimination of prostatic carcinoma in the PZ and CG was relative peak enhancement. If relative peak enhancement was not used, then peak enhancement was optimal in the PZ, and washout was optimal in the CG. Poor-to-moderate correlation was present between the dynamic parameters or T2 relaxation rate in carcinoma and the tumor stage, Gleason score, patient age, tumor volume, and prostate-specific antigen

Succinate dehydrogenase (SDH)-deficient renal carcinoma has been accepted as a provisional entity in the 2013 International Society of Urological Pathology Vancouver Classification. To further define its morphologic and clinical features, we studied a multi-institutional cohort of 36 SDH-deficient renal carcinomas from 27 patients, including 21 previously unreported cases. We estimate that 0.05% to 0.2% of all renal carcinomas are SDH deficient. Mean patient age at presentation was 37 years (range, 14 to 76 y), with a slight male predominance (M:F=1.7:1). Bilateral tumors were observed in 26% of patients. Thirty-four (94%) tumors demonstrated the previously reported morphology at least focally, which included: solid or focally cystic growth, uniform cytology with eosinophilic flocculent cytoplasm, intracytoplasmic vacuolations and inclusions, and round to oval low-grade nuclei. All 17 patients who underwent genetic testing for mutation in the SDH subunits demonstrated germline mutations (16 in SDHB and 1 in SDHC). Nine of 27 (33%) patients developed metastatic disease, 2 of them after prolonged follow-up (5.5 and 30 y). Seven of 10 patients (70%) with high-grade nuclei metastasized as did all 4 patients with coagulative necrosis. Two of 17 (12%) patients with low-grade nuclei metastasized, and both had unbiopsied contralateral tumors, which may have been the origin of the metastatic disease. In conclusion, SDH-deficient renal carcinoma is a rare and unique type of renal carcinoma, exhibiting stereotypical morphologic features in the great majority of cases and showing a strong relationship with SDH germline mutation. Although this tumor may undergo dedifferentiation and metastasize, sometimes after a prolonged delay, metastatic disease is rare in the absence of high-grade nuclear atypia or coagulative necrosis.