[926] Atypical Cribiform Lesions of the Prostate: Implications for Diagnosis in Prostate Biopsies
M Zhou, C Magi-Galluzzi, R Shah. Cleveland Clinic, Cleveland, OH; University of Michigan, Ann Arbor, MI
Background: Atypical cribiform lesions of the prostate (ACL) are cribiform structures consisting of cytologically malignant cells with partial or complete basal cell lining. They can represent 
intraductal carcinoma which is invariably associated with high grade prostate carcinoma (PCa) (cancer associated ACL, ACL-PCa), or cribiform high grade PIN which can be an isolated finding not associated with PCa (non-cancer associated ACL, ACL-nonPCa). We report the histological differences of these 2 lesions on radical prostatectomy (RP) and implications for diagnosis in prostate biopsies (NBX).
Design: RP was reviewed for ACL. The presence of basal cells was confirmed by basal cell immunostaining. ACL intermixed with, or within 2 mm from the border of PCa was categorized as ACL-PCa. The following histological features were reviewed: number of ACL/prostate gland, size, glandular contour (round, irregular, branching), architectural pattern (trabecular, cribiform, solid), comedonecrosis, nuclear feature (round and uniform, round with varying sizes, pleomorhpic, giant nuclei [>6x adjacent nuclei]).
Results: 35 cases with ACL-PCa and 17 cases with ACL-nonPCa were studied (Table). The mean number of ACL per prostate was 25.3 for ACL-PCa and 2.4 for ACl-nonPCa (p=0.008). The size ranged from 0.2-6.5 mm for ACL-PCa, and 0.2-1mm for ACL-nonPCa. The branching contour was present in 29/35 ACL-PCa, but in only 1/17 ACL-nonPCa (p<0.001). The architectural patterns were not different between the two (p=0.21). Comedeonecrosis was present in 14/35 ACL-Pca, and none of ACL-nonPCa (p=0.002). The pleomorphic nuclei or giant nuclei that were >6X of the adjacent nuclei were present in 9 of ACL-PCa, but none of ACL-nonPCa (p=0.049).
| ACL-PCa | ACL-nonPCa | P value | |
| # Cases | 35 | 17 | |
| Mean # of ACL/prostate gland | 25.3 | 2.4 | 0.008 |
| Size (range, mm) | 0.2-6.5 | 0.2-1 | |
| Branching glandular contour | 29/35 | 1/17 | <0.001 |
| Comedonecrosis | 14/35 | 0/17 | 0.002 |
| Nuclear features: pleomorhpic or giant (x6 adjacent nuclei) | 9/35 | 0/17 | 0.049 |
Conclusions: NBXs demonstrating several features of large foci, architectural complexity with large branching glands, pleomorphic or giant nuclei, or comedonecrosis are invariably associated with invasive cancer. A note indicating such should be included in the biopsy report. As there is overlap in histological appearance between ACL-PCa and ACL-nonPCa, the presence of atypical cribriform lesions in NBX should prompt repeat biopsy to rule out concomitant PCa.
Category: Genitourinary (including renal tumors)
Tuesday, March 10, 2009 11:30 AM
Platform Session: Section A, Tuesday Morning