A case of fatty replacement of pancreatic body and tail successfully underwent pancreatoduodenectomy without pancreatic reconstruction followed by adequate control of diabetes mellitus

We report a case of fatty replacement of pancreatic body and tail (FRPBT) with an intraductal papillary mucinous neoplasm (IPMN) in a subject undergoing pancreatoduodenectomy (PD). A 75-year-old woman found in computed tomography (CT) to have a multilocular cystic pancreatic head tumor during a checkup for poor diabetes mellitus control was found in magnetic resonance imaging (MRI), endoscopic retrograde cholangiopancreatography (ERCP), and endoscopic ultrasound (EUS) to have pancreatic head mixed type IPMN. CT and MRI also showed severe atrophy and steatotic pancreatic body and tail change indicating FRPBT. ERCP showed the main pancreatic duct to be obstructed at the pancreatic body. She thus underwent PD without pancreatic reconstruction for IPMN with FRPBT. Only thick fatty tissue was recognized macroscopically in the pancreatic body and tail. Postoperative insulin control of diabetes mellitus was adequate, without hyperglycemia or hypoglycemia, resembling total pancreatectomy results. Histopathologically, the cystic pancreatic head tumor was intraductal papillary mucinous adenoma and the islets of Langerhans remained in the pancreatic body portion replaced by fatty tissue. PD is considered appropriate in FRPBT because postoperative insulin control is comparatively stable because the islets of Langerhans remain in pancreatic fatty tissue.