Atypical adenomatous hyperplasia of the prostate mimicking adenocarcinoma lesion: case report and literature review.

The diagnosis of prostate cancer is challenging because of the existence of lesions that mimic adenocarcinoma. Such a lesion is atypical adenomatous hyperplasia (AAH) or adenosis, which represents a proliferation of crowded, small to medium glands with basal cell layer invariably present, but often inconspicuous on routine stains. The importance of the lesion lies in the potential for being misdiagnosed as low-grade adenocarcinoma (Gleason 1 or 2). We present the case of a male patient, who suffered a transurethral prostatic resection surgery. Histopathological examination showed benign prostatic hyperplasia with a focus of crowded glands with a nodular appearance. The presence of basal cell was assessed using high molecular-weight cytokeratin (HMWCK), clone 34βE12 and p63 immunostaining, which revealed discontinuous positive immunostaining. In adenocarcinomas, the basal cell layer is absent. This case highlights the usefulness of 34βE12 antibodies, avoiding a false positive diagnosis of cancer, with negative consequences on the patient's psychological condition and treatment costs. We recommended the follow-up of the patient.