The Gleason pattern 4 in radical prostatectomy specimens in current practice - Quantification, morphology and concordance with biopsy.

PURPOSE: The upgrading of a prostate acinar adenocarcinoma grade group 1 (GG1) between needle biopsy and prostatectomy is common. The extent of high-grade tumor and cribriform morphology are currently suggested as prognostic factors. METHODS: We reviewed 159 prostatectomy specimens from a private laboratory and an academic/public institution in Salvador, Bahia. RESULTS: Tumors signed as GG1 at biopsy were upgraded in 59% of all cases. These tumors showed a low frequency of non-focal extraprostatic extension (one case, 3%), extensive positive surgical margins (two cases, 6%) and seminal vesicle invasion (one case, 3%). Among GG2 and GG3 tumors at prostatectomy, the percentage of Gleason pattern 4 (Gp4) involving the gland at ≤1%, 2-5% and >5% was associated with extensive extraprostatic extension (9%, 8% and 42%, respectively) and seminal vesicle invasion (1%, 10% and 31%, respectively). The volume of Gp4 of ≤1ml, >1 to 2ml and >2ml was associated with extensive extraprostatic extension (8%, 26% and 38%, respectively), seminal vesicle invasion (2%, 21% and 33%, respectively) and non-focal positive surgical margins (12%, 26% and 29%, respectively). Some GG2 tumors (~20%) indeed showed at least one measurement of Gp4 higher than one quarter of GG3 carcinomas. Cribriform morphology showed no significant associations for other adverse pathologic prognostic factors. CONCLUSION: Upgrading from GG1 to GG2 is associated with a very low frequency of morphologic features associated with poor prognosis. Routine quantification of Gp4 is feasible in radical prostatectomy products and seems to better stratify tumors regarding the association with other morphologic parameters of prognostic importance.

Assessment of the circumferential margins, extraprostatic extension and Gleason score in radical prostatectomy specimens: Comparison of a partial embedding method with supplemental total inclusion of peripheral tissues.

BACKGROUND: Recent data suggest that up to 21% of positive circumferential margins (PCM) and 47% of extraprostatic extension (EPE) samples may be missed when partial embedding methods are employed. Kim and colleagues (2009) suggested that total inclusion of the periphery (3mm rim) of the prostate prevented the failure to detect PCM and EPE. DESIGN: Radical prostatectomy specimen (n=148) slides were reviewed after adoption of a protocol that included a ∼3 mm rim of peripheral tissues. We evaluated whether the analysis of supplemental slides of prostate periphery changed margin status, presence of EPE, Gleason score and extent of PCM and EPE. RESULTS: Partial sampling resulted in missing 29% of PCM and 20% of EPE without using data from the supplemental slides of prostate periphery. Changes from focal to extensive disease were found in 11/21 (52%) cases of positive circumferential margins and in 5/13 (38%) cases of extraprostatic extension. Changes in the Gleason score were uncommon. CONCLUSIONS: These results indicate the importance of including all the prostate peripheral tissue for microscopic analysis when partial embedding methods are adopted.