[Unique papillary cystadenocarcinoma of the prostate with endocrine cells].

Histological examination of prostatic tumour of a man who died at the age of 71, revealed dark-cell small-acinar carcinoma with scattered papillary cystadenocarcinomatous structures. The latter, apart from two types of epithelial cells (dark granular and clear cells) contained argyrophilic endocrine cells detected by Grimelius' staining. These cells were absent in the dark-cell small-acinar areas. It is suggested that acinar and cystadenopapillary structures differ in their histogenesis.