[Histological findings in 100 needle prostatic biopsies and original diagnosis of benignity]

Detailed revision of prostate biopsies with benign alterations may show potentially malignant lesions limited to isolated fields, which may be overviewed in routine analysis.

To exam the morphological alterations in patients with suspicious of prostatic carcinoma and benign diagnosis in needle biopsies.

During 2000-2001, one hundred consecutive patients with first prostate biopsy diagnosed as benign were included. Biopsies were performed by sextants or modified sextants technique. Slides were reviewed by two observers with knowledge of original diagnosis and this was accepted or modified in accordance to the findings found during the review.

Patients age ranged between 57 and 79 years old. Nine per cent of biopsies originally diagnosed as benign revealed different potentially malignant lesions, which should be noted due to possible association with carcinoma. In this group, there were five biopsies with atypical small acinar proliferation, three with few isolated glands with xanthomatous cytoplasm, and one with scarce atypical cells in the prostatic stroma. In contrast with Caucasian and Afro-American population, frequency of high grade intraepithelial neoplasia in needle biopsy seems to be very low and this lesion was not found in any of the 100 biopsies reviewed. Some lesions that simulate carcinoma, as atypical basal cell hyperplasia, post-atrophic hyperplasia, and adenosis were diagnosed as benign, and there was none false positive result.

A small but significant group of the biopsies originally diagnosed as benign lesions, showed atypical lesions in isolated fields that were overlooked in the routine analysis. It is necessary the urologist to ask for a directed review of the biopsies if clinical and laboratory data strongly suggest prostatic carcinoma. Additional histological cuts, immunohistochemical studies and more than one observer may increase the frequency of detection of potentially malignant lesions.