Atypical stromal hyperplasia of the prostate.

This paper reports a case of atypical stromal hyperplasia (ASH) of the prostate, i.e. a proliferation of stromal cells with scattered atypical nuclei, growing between benign prostatic glands. This is a rare lesion, but at least 36 cases have been reported. Although most ASHs arise in the transition zone in conjunction with benign prostatic hyperplasia, the current lesion was found in the peripheral zone of a 58-year-old man who underwent radical prostatectomy because of prostatic adenocarcinoma. The clinical impact of ASH is discussed and the literature reviewed.