Adenosis of the prostate: a dysplastic lesion that can be confused with prostate adenocarcinoma.

A ten-year period, 1966 through 1975, provided 2842 prostate specimens at The Wesley Medical Center, These specimens were classified as (1) adenocarcinoma, (2) adenosis, or (3) hyperplasia. During a follow-up period of 5--15 years (average 7.7 years), prostate carcinoma developed in seven of 108 patients (6.5%) with adenosis. During the same follow-up period prostate carcinoma developed in at least 84 of 2263 patients (3.7%) with hyperplasia. Adenosis is considered to be a dysplastic lesion because patients with histologic lesions limited to adenosis have approximately the same likelihood of prostate carcinoma developing as patients with hyperplasia.