Multifocal pancreatic intraepithelial neoplasia (PanIN) lesions of the branch ducts associated with lobular parenchymal atrophy in a Japanese patient diagnosed to have familial pancreatic cancer

This report presents a case of Japanese familial pancreatic cancer (FPC) with multifocal pancreatic intraepithelial neoplasia (PanIN) lesions of the branch ducts probably associated with lobular parenchymal atrophy. The risk of pancreatic cancer is significantly increased in those associated with FPC, and this risk increases with increasing numbers of affected first-degree relatives, but there have been four Japanese cases reported. A 63-year-old Japanese male was referred to the hospital for evaluation and treatment of a pancreatic head tumor. His family history included pancreatic cancer in two-first-degree relatives and three-second-degree relatives. A pylorus-preserving pancreatoduodenectomy with a regional lymphadenectomy and intraoperative radiotherapy were performed. The histological findings of the main tumor showed a moderately differentiated tubular adenocarcinoma in the head of the pancreas without metastasis of the resected lymph nodes. Interestingly, multifocal PanIN lesions in the branch ducts were individually developed and some of these lesions were probably associated with small lesions of lobular parenchymal atrophy. He remained in good condition for 37 months after the operation. Although the concept of FPC has not been clearly established in Japan, nationwide registries of FPC are probably useful for management of FPC patients.