Benign mimics of prostatic adenocarcinoma on needle biopsy.

Various benign processes can mimic prostatic adenocarcinoma on needle biopsy. These processes include glandular lesions such as adenosis, atrophy, VMGH, and BCH; inflammatory conditions such as acute and chronic or granulomatous prostatitis; and the effects of therapy such as external beam radiation or androgen deprivation. Normal benign prostate tissues including seminal vesicles, paraganglia, and ganglion cells may also be confused histologically with prostatic adenocarcinoma in needle biopsy specimens. With careful attention to architectural and cytologic features, these lesions can be readily distinguished from prostatic adenocarcinoma in most cases. In difficult cases, immunohistochemical studies using antibodies to PSA and high molecular weight cytokeratin (34 beta E12) have proved to be an invaluable adjunct in the differential diagnosis of prostatic adenocarcinoma on needle biopsy.