Proliferative inflammatory atrophy (PIA) is a premalignant prostatic change with high occurrence in human prostate and it has been recently observed in dogs. This research aimed to verify the morphologic aspects of the PIA in canine prostate. It was studied 43 glands of adult dogs of several breeds and sizes and with or without a history of prostatic disease. PIA focus was characterized by dysplastic epithelium, atrophic acini formed by several layers of cells with variable degrees of anisocytosis, anisokaryosis, reduced amount of cytoplasm and nuclei with prominent nucleoli. The epithelial changes were always accompanied by periacinar interstitial infiltrate composed of mononuclear cells, especially lymphocytes. The histomorphological evaluation showed occurrence of 65% of PIA. Out of these, 39% were PIA with discrete inflammatory infiltration, 42% PIA with moderate infiltrate and 19% PIA with marked infiltration. Thus, it was possible to characterize the PIA in the canine prostate which had high occurrence. The histomorphological characterization of canine PIA is considered of great importance because the premalignant characteristic of it have been studied in human prostate. The canine prostate can be used as an experimental model of human PIA, because the lesion is similar in both species.
dog; PIA; prostatic dysplasia
