Prostatic atrophy is a benign lesion that may mimic adenocarcinoma histologically and on imaging. It is more frequent in the peripheral zone and has gained importance with the increasing use of needle biopsies. Diffuse atrophy occurs secondarily to radiotherapy and/or endocrine therapy. Inflammation and/or chronic local ischemia may cause focal atrophy with an increasing frequency in age. Atrophy may be classified morphologically into diffuse and focal. The latter may be partial, complete or combined. Partial focal atrophy is the most frequent mimicker of adenocarcinoma on needle biopsies. Complete focal atrophy may be subtyped into simple, sclerotic and hyperplastic (or postatrophic hyperplasia). Combined lesions are frequent and partial atrophy may precede complete atrophy. The several morphologic types of focal atrophy may represent a morphologic continuum and the hyperplastic (or postatrophic hyperplasia) subtype seems to be at the extreme end of this continuum. Chronic inflammation associated to focal atrophy (proliferative inflammatory atrophy) has been linked to high-grade prostatic intraepithelial neoplasia and/or carcinoma. This link, however, remains controversial in the literature. The question whether inflammation directly produces tissue damage and atrophy or some other insult induces atrophy directly, with inflammation occurring secondarily, is still unresolved. An intriguing finding that needs further studies is a possible association of extent of atrophy to serum PSA elevation.36401-9