A case of pancreatic intraductal tubulopapillary neoplasm (ITPN) mimicking a small ductal carcinoma

Abstract

A 75-year-old man had been followed up after treatments of lung cancer, retroperitoneal fibrosis and malignant lymphoma at our hospital. Abdominal CT in February 2013 revealed dilatation of the main pancreatic duct in the body and the tail. MRCP and ERCP showed a nodular mass, 18 × 8 mm in size, in the pancreatic body, as well as dilatation of the distal pancreatic duct. Distal panreatectomy and splenectomy were performed under the preoperative diagnosis of early-stage pancreatic ductal carcinoma. However, the pathological diagnosis of the resected pancreatic mass was intraductal tubulopapillary neoplasm (ITPN) . Histochemical examinations showed positive results for MUC1 on the luminal side of the pancreatic ducts, and negative results for MUC2 and MUC5AC. Acinar cell carcinoma and malignant lymphoma were excluded on the basis of the negative staining results for trypsin and Bcl-10. ITPN is a rare and relatively newly described clinical type of pancreatic neoplasm. This case serves to emphasize that we must bear in mind the possibility of ITPN in the differential diagnosis of pancreatic tumors.