NEUROENDOCRINE STAINING IN MALIGNANT, HYPERPLASTIC, AND ATROPHIC PROSTATE TISSUE

The presence of neuroendocrine cells in both benign and malignant pros tatic epithelium has been documented. To categorize the incidence and extent of these cells further, we studied staining of chromogranin A ( ChA) and neuron-specific enolase (NSE) in acinar-type adenocarcinoma o f the prostate and in the surrounding atrophic prostate glands. Staini ng of relatively small portions of tissue using multitumor blocks show ed that 10 of 21 (48%) acinar-type adenocarcinomas of the prostate con tained neuroendocrine cells. However, when larger sections of the 11 i nitially negative tumors were stained for ChA and NSE, an additional s ix tumors showed focal neuroendocrine positivity. Only one tumor was N SE-positive and ChA-negative. These results indicate that (a) ChA is a more sensitive marker than NSE for neuroendocrine differentiation in prostate carcinoma; and (b) although benign prostatic tissue stains ex tensively enough for neuroendocrine cells to be detected on the small sections used in the multitumor blocks, the positivity in prostatic ad enocarcinoma may be focal and larger sections therefore produce more r eliable results.