2017 Volume 32 Issue 1 Pages 87-92
A 65-year-old man with a pancreatic mass detected by abdominal CT was referred to our hospital for further examination and treatment. Abdominal CT and MRI showed a multi cystic mass in the pancreatic body with communication to main pancreatic duct. EUS showed a 27mm hypoechoic multi cystic mass with a mural nodule. Cytology of the pancreatic juice showed mucinous cells with low-grade dysplasia. The patient was diagnosed with invasive adenocarcinoma derived from intraductal papillary mucinous neoplasm (IPMN) and we performed distal pancreatectomy and splenectomy with lymph node dissection. The resected specimen showed a whitish solid mass involving dilatation of the pancreatic branch duct. Histopathological examination showed fibrosis, dense infiltration of chronic inflammatory cells composed of IgG4-positive plasma cells and obliterative phlebitis around the dilated pancreatic ducts associated with IPMN low-grade dysplasia. The histological diagnosis was focal autoimmune pancreatitis (AIP) associated with branch type IPMN.
