LAUSR

Objectives Pancreatic intraepithelial neoplasia (PanIN) is the currently preferred designation for putative preneoplastic changes in the pancreas. There are few data for the incidence of PanIN in the general population. Our goal was to determine the incidence of PanIN in a large group of pancreases obtained at autopsy. Methods Slides stained with hematoxylin and eosin were scanned to count PanIN. Results We found multiple PanINs in most pancreases and at least 1 in 86.4% of 154 pancreases when multiple slides (8–12) from each were examined. The average age at autopsy was 62 years, and 90% of the patients were 40 years or older. Several questions were raised by our observations. Should a minimum size be defined for classification as PanIN? Do PanINs occur in lesions that apparently arise from acinar to ductal metaplasia? Does squamous metaplasia in PanIN have any special significance, and do purely squamous lesions have preneoplastic significance? Conclusions We conclude that the incidence of PanIN is higher than previously reported.