Abstract
Cholangiocarcinoma is a rare and aggressive malignancy of the biliary epithelium that frequently presents with nonspecific symptoms and is often diagnosed at an advanced stage. Diagnosis may be delayed when coexisting hepatobiliary conditions obscure the underlying pathology, and conventional imaging or endoscopic retrograde cholangiopancreatography (ERCP) may fail to identify distal bile duct lesions, particularly when biliary access cannot be achieved. We report the case of an 81-year-old man who presented with findings initially suggestive of gallstone pancreatitis but with evolving features concerning for persistent biliary obstruction. Imaging demonstrated pancreatitis with biliary dilation but no definitive obstructing lesion. ERCP was pursued due to persistent cholestatic liver enzyme abnormalities, common bile duct dilation, and concern for an underlying obstructive process; however, cannulation of the common bile duct was unsuccessful. Subsequent percutaneous transhepatic biliary drainage (PTBD) was performed to establish biliary access. Through this access, SpyGlass (Boston Scientific, Marlborough, MA, USA) single-operator cholangioscopy was advanced via the percutaneous tract, revealing an irregular distal bile duct stricture. Targeted biopsies confirmed distal cholangiocarcinoma. The patient's hospital course was complicated by Escherichia coli bacteremia secondary to biliary obstruction. Given poor surgical candidacy, internal biliary drainage was achieved via endoscopic ultrasound-guided choledochoduodenostomy with placement of a lumen-apposing metal stent. Despite appropriate biliary decompression, the diagnosis represented advanced malignancy requiring palliative management. This case highlights the importance of maintaining suspicion for malignant biliary obstruction in atypical presentations of pancreatitis and demonstrates the role of alternative cholangioscopy access routes in establishing diagnosis following failed ERCP.