Focal prostatic atrophy: mimicry of prostatic cancer on TRUS and 3D-MRSI studies.

Prostatic atrophy which represents a form of adaptive response to injury most commonly to inflammation and/or chronic ischemia is a histological abnormality frequently found in prostate biopsies and autopsies. Although commonly found, this lesion is rarely reported in the prostatic biopsy reports. It is well known that histologically focal prostatic atrophy (FPA) is one of the most frequent mimics of prostatic adenocarcinoma. On conventional and color Doppler transrectal ultrasound and on magnetic resonance spectroscopic imaging studies (MRSI), FPA may also simulate prostate cancer. Thus, this entity should be considered together with prostatitis as an important cause of false-positive results in MRSI of the prostate. It has been shown that there is a positive and significant association between extent of FPA in biopsies and serum total or free PSA elevation. For this reason, pathologists should include the presence of FPA in the pathology report of a prostatic biopsy, particularly in those patients with absence of cancer. When extensive FPA is the only finding in patients with several negative prostatic biopsies, this lesion may be the source for PSA elevation.