Mimickers of prostate cancer in needle biopsies.

The diagnosis of prostate cancer is made based on the architecture of the glandular proliferation and nuclear atypia, but some normal structures (seminal vesicle, Cowper's glands, prostatic central zone) or nonneoplastic proliferative lesions can mimic carcinoma. Of the 3 patterns of prostate cancer--solid, cribriform, and microglandular, the microglandular pattern is the one that imitates carcinoma most frequently on needle biopsy. The demonstration of basal cells can be the best method to identify these prostate cancer mimickers.