Synchronous solid pseudopapillary neoplasm and intraductal papillary mucinous neoplasm of the pancreas: report of a case.

Solid pseudopapillary neoplasm (SPN) of the pancreas, most commonly found in young female subjects, is a rare neoplasm with low potential for malignancy. We report an unusual case of a 66-year-old male patient who had a simultaneous malignant SPN and an intraductal papillary mucinous adenoma (IPMA) of the pancreas. The patient was admitted to our department for the evaluation of the main solid tumor with calcification and small multilocular cystic lesions apart from the main tumor in the pancreatic head. We performed pylorus-preserving pancreaticoduodenectomy to treat the calcified tumor and multilocular cystic lesions. The diagnosis of malignant SPN was confirmed on the basis of histological invasion to the adjacent structures. The separate cystic lesions were diagnosed as a branch-type IPMA. The synchronous occurrence of IPMA and SPN in the present case did not demonstrate that there were tumors maintained through the common abnormal Wnt signaling pathway by immunohistochemical study. To our knowledge, this is the first known case of synchronous SPN and IPMA of the pancreas.