DISTRIBUTION PATTERN OF BASAL CELLS DETECTED BY CYTOKERATIN-34-BETA-E12 IN PRIMARY PROSTATIC DUCT ADENOCARCINOMA

Primary prostatic duct adenocarcinoma, initially labeled as endometrio id carcinoma of the prostate, is a rare neoplasm that displays exophyt ic growth into the prostatic urethra with involvement of prostatic duc ts. Because this tumour arises from preexisting epithelia, there is a possibility that a remnant basal epithelium may be seen in association with these tumours. If this hypothesis is correct, then prostatic duc t adenocarcinoma may possibly be mistaken for high-grade prostatic int raepithelial neoplasia (PIN) on needle biopsies. The distribution of b asal cells in this tumour has not been described previously. Nine case s of prostatic duct adenocarcinoma and prostatic adenocarcinoma with f ocal ductal differentiation were studied immunohistochemically with an tibodies specifying cytokeratin 34 beta E12, prostate-specific antigen (PSA), and prostatic acid phosphatase (PAP). All cases were positive for PSA and PAP. In some areas of the tumour in eight cases there was a continuous and discontinuous layer of basal cells surrounding island s of carcinoma. This was found with cribriform, comedo, solid, and pap illary components of ductal type adenocarcinoma. It is necessary to be aware of the presence of basal cells in association with primary pros tatic duct adenocarcinoma. Differentiation of high-grade PIN from this lesion should depend on complex architectural characteristics and Cyt ologic features rather than presence of a basal cell layer. This findi ng confirms that the solid, cribriform, papillary, and comedo componen ts initially grow intraluminally within ducts before invasion into sur rounding stroma occurs.