A case of intraductal papillary-mucinous neoplasm of the pancreas penetrating into the stomach and spleen successfully treated by total pancreatectomy

BACKGROUND: Intraductal papillary-mucinous neoplasms (IPMNs) are potentially malignant intraductal epithelial neoplasms that sometimes penetrate into other organs. To the best of our knowledge, no report has yet described a case with penetration into the spleen. We recently encountered a case of IPMN with penetration of the stomach and spleen that was successfully treated by total pancreatectomy. CASE PRESENTATION: A 70-year-old female visited our hospital with a complaint of fever and abdominal pain. Contrast-enhanced computed tomography (CT) revealed dilatation of the main pancreatic duct in the entire pancreas and penetration into the stomach and spleen. Upper gastrointestinal endoscopy revealed mucin extruding from four openings of the fistula in the stomach. No malignancy was detected based on cytology of the mucin. Inflammation markers and tumor markers (CEA, CA19–9) were elevated in the blood. The pre-operative diagnosis was IPMN of main pancreatic duct type penetrating into the stomach and spleen. A total pancreatectomy and splenectomy were performed, combined with distal gastrectomy including resection of the fistulas between the pancreas and stomach. No postoperative complications were noted. Histopathological examination of the resected specimen revealed atrophy of the pancreatic parenchyma, and the main duct of the pancreas was filled with mucin. Mucin-producing malignant tumor cells were detected in the epithelium of the main pancreatic duct with no signs of invasion. No malignancy was found at the fistulas between the pancreas and stomach or spleen. The patient was finally diagnosed with non-invasive intraductal papillary-mucinous carcinoma (IPMC) of main pancreatic duct type. Mechanical penetration was suspected as a mechanism of the penetration. The patient remained disease-free without evidence of recurrence more than 15 months after the operation. CONCLUSION: Though IPMNs sometimes penetrate into other adjacent organs, penetration into two organs, including the spleen, is rare. The rare case of IPMC penetrating into the stomach and spleen presented here was treated successfully by total pancreatectomy.