Focal eosinophilic hypertrophic cells of the rat pancreas.

Focal spontaneously occurring eosinophilic hypertrophic cells, histomorphologically resembling oncocytes and hepatocytes, were observed in the pancreas from 11 (0.3%) of 4,177 Sprague-Dawley rats, 3 to 26 months old. The age of these eleven rats ranged from 13 to 25 months. The incidence was not different between sexes. The altered cells were usually seen in the peri-insular area. Two types of foci, uniform and pleomorphic, were classified on the basis of uniformity of size of the altered cells within a focus. The origin and nature were not determined for the altered cells/foci reported in this study but they were not considered to be neoplastic.