Vusal Aliyev, Kentaro Yasuchika, Amr Badawy, Ahmed Hammad, Mariyo Rokutan-Kurata, Tetsuya Tajima, Ken Fukumitsu, Koichiro Hata, Hideaki Okajima, Shinji Uemoto
Background Intraductal papillary mucinous neoplasms arise from the main pancreatic duct and/or branch ducts and are characterized by intraductal papillary proliferation of mucin-producing epithelial cells exhibiting various degrees of dysplasia. The intraductal papillary mucinous neoplasms of the pancreas rarely penetrates others organs. Case presentation We report an unusual case of intraductal papillary mucinous neoplasms fistulating into the stomach in a patient who previously underwent distal gastrectomy. Pancreatoduodenectomy was performed with resection of fistulisation site at the posterior gastric wall. The histopathological examination of the surgical specimen showed high-grade dysplasia with invasive carcinoma. Conclusion In treatment of intraductal papillary mucinous neoplasms with fistula, the fistula should be removed to avoid a possible malignant dissemination. The extent of resection depends on the extent of cancer invasion.