Epithelial alterations in pancreatic ducts may have a premalignant nature. We compared the incidence of different lesions in 49 pancreatic cancer specimens compared to 100 controls. Simple hyperplasia, mucosecretory metaplasia and pyloric metaplasia were evenly distributed among groups. In contrast, papillary hyperplasia, intestinal metaplasia and dysplasia were significantly more frequent in pancreas with carcinoma. Therefore, these lesions may have a precancerous nature.