Abstract
A 61-year-old man visited our hospital because of diabetes detected on a health examination. Enhanced-computed tomography (CT) revealed a diffuse dilated main pancreatic duct filled with a solid mass and a filling defect in the splenic vein. Abdominal ultrasonography revealed a rough low echoic mass with an anechoic lesion filling in the main pancreatic duct. A total pancreatectomy was performed on the basis of a preoperative diagnosis of intraductal papillary mucinous neoplasm. The intraductal tumor was histopathologically atypical cylinder epithelium with a swollen nucleus exhibiting tubular or papillary growth. Mucus was not observed, but necrosis was present. Because immunohistochemistry was CK7 and CK19 positive and MUC2 negative, the tumor was diagnosed as intraductal tubulopapillary neoplasm (ITPN) with a tumor thrombus in the splenic vein. ITPN is a new category of intraductal pancreatic neoplasms that was first described in WHO classification in 2010. ITPN should be considered during differential diagnosis of intraductal pancreatic neoplasms.
