Mergence of partial and complete atrophy in prostate needle biopsies: a morphologic and immunohistochemical study.

Partial atrophy is the most common benign lesion that causes difficulty in the differential diagnosis with adenocarcinoma of the prostate. Very few studies described, illustrated, and discussed the concomitance of partial atrophy with complete atrophy in prostatic needle biopsies. The study group comprised 75 needle prostatic biopsies corresponding to 67 patients. Focal prostatic atrophy was present in all biopsies. Complete atrophy was subtyped into simple atrophy, sclerotic atrophy, and hyperplastic atrophy (or postatrophic hyperplasia). We analyzed the presence of inflammation in the atrophic foci and immunohistochemistry was performed for p63, 34betaE12, and PSA. Partial atrophy and complete atrophy were present concomitantly in 47/75 (63%) biopsies. In 20/75 (27%) biopsies, there were areas with mergence of partial atrophy and complete atrophy. We illustrate morphologic transitions between these lesions in the same gland. Using immunohistochemistry, the aberrant phenotypic expression in the secretory compartment in all subtypes of complete atrophy highlighted the morphologic transitions between partial and complete atrophies in the same gland. An intriguing finding was the absence of chronic inflammation in partial atrophy foci as well as in areas of mergence between these lesions. Inflammation was present only in isolated complete focal atrophy foci. Partial atrophy seems to be part of a morphologic spectrum of focal prostatic atrophy and probably precedes complete atrophy. The question of whether the inflammation produces tissue damage and prostatic atrophy or whether some other insults like ischemia induces the tissue damage and atrophy directly, with inflammation occurring secondarily, is still unsettled.