Direct peroral cholangioscopy and pancreatoscopy for diagnosis of a pancreatobiliary fistula caused by an intraductal papillary mucinous neoplasm of the pancreas: a case report.

Here, we report a case of a pancreatobiliary (PB) fistula caused by an intraductal papillary mucinous neoplasm (IPMN) of the pancreas. The PB fistula was suspected after endoscopic retrograde cholangiopancreatography (ERCP) and diagnosed after direct visualization with a direct peroral cholangioscopy and pancreatoscopy by using an ultra-slim endoscope. No previous reports exist on the precise diagnosis of a PB fistula with direct peroral cholangioscopy and pancreatoscopy. In our case report, a 69-year-old man underwent an ERCP because of a pancreatic head mass and biliary tract obstruction. During ERCP, a fistula between the common bile duct (CBD) and main pancreatic duct (MPD) was suspected. After endoscopic sphincterotomy, we examined both the CBD and MPD with an ultra-slim videoendoscope (GIF-N260; Olympus Optical Co, Tokyo, Japan) under direct visualization and biopsy of the mass. The analysis of the biopsy specimen confirmed this mass to be an IPMN of the pancreas. When we examined the CBD, one fistula with copious mucin secretion was identified at the distal CBD. In conclusion, direct peroral cholangioscopy and pancreatoscopy using the ultra-slim endoscope is an efficient tool for diagnosis of PB fistula and pancreatic IPMN.