A case showing sclerosing adenosis and an unusual form of basal cell hyperplasia of the prostate.

We describe an unusual case of benign prostatic hyperplasia that demonstrated florid sclerosing adenosis--an uncommon lesion that may be confused with prostate carcinoma. Immunohistochemistry utilizing Keratin 903, a basal cell-specific antikeratin antibody, was useful in identifying basal cells in sclerosing adenosis, thus verifying its benign nature. In addition, this case had an unusual form of basal cell hyperplasia that resembled basaloid carcinomas (adenoid cystic carcinoma) involving the prostate.