Adenocarcinoma of the prostate involving the rectum.

Five cases of prostatic carcinoma invading the rectum were found on reviewing 161 prostatic carcinomas over a five-year period. A summary of the clinical and laboratory findings of these cases is given. A review of previous reports in the literature and discussion of the modality of presentation and methods of diagnosis of this entity are presented. The importance of differentiating a primary rectal carcinoma from a prostatic carcinoma involving the rectum is emphasized.