Presentation Authors: Mustafa Deebajah*, Shannin Carskadon, Sean Williamson, Nilesh Gupta, Nallasivam Palanisamy, James Peabody, Mani Menon, Shaheen Alanee, Detroit, MI
Introduction: Comedonecrosis has always been assigned Gleason pattern 5. Recent recommendations suggest against the grading of intraductal carcinoma. We hypothesized that prostatic adenocarcinoma with comedonecrosis may be frequently intraductal and therefore prostate cancer grading system may need to be revised
Methods: We searched our pathology database from 2014-2018 for radical prostatectomy cases with documented comedonecrosis (specific grade patterns accounting for pattern 4 and 5 have been documented over this period). From an initial cohort of 52 cases with reported comedonecrosis, 40 cases were retrieved and had identifiable areas of comedonecrosis on additional whole mount slides prepared for immunohistochemistry. Immunohistochemical staining was performed for prostatic basal cell markers p63 and high molecular weight cytokeratin on whole-mount tumor blocks with the largest areas of comedonecrosis.
Results: In 24 cases (60%), the comedonecrosis was located only in intraductal carcinoma, whereas seven cases (18%) had both intraductal carcinoma and invasive carcinoma with necrosis. In nine cases (23%), the comedonecrosis was located exclusively in cribriform invasive cancer. Five cases (13%) had comedonecrosis in the extraprostatic extension. The cases were overwhelmingly high-stage, with 15 pT3a (38%) and 19 pT3b (48%) with 12 (30%) having positive lymph nodes. Thirty-three cases (83 %) had other patterns of Gleason pattern 5 (single cells, solid growth), in addition to comedonecrosis.
Conclusions: A high proportion of prostate cancer with comedonecrosis is intraductal. Future modifications of prostate cancer grading should reconsider how intraductal carcinoma with comedonecrosis is approached.