A Challenging Diagnosis of Eosinophilic Cholangitis Requiring Resection of Extrahepatic Bile Ducts.

Eosinophilic cholangitis (EC) is a rare benign disease characterized by transmural eosinophilic infiltration of the biliary tree that may result in biliary stricture and obstructive jaundice. The pathophysiology remains unknown but is theorized to involve an allergic mechanism. EC is diagnostically challenging as it may mimic cholangiocarcinoma (CCA) clinically and radiographically and involves a broad differential diagnosis including benign and malignant pathologies. In addition to tumor markers, ultrasonography, contrast-enhanced computed tomography (CT), and magnetic resonance cholangiopancreatography (MRCP), proper evaluation of malignant processes may need biopsy through endoscopic retrograde cholangiopancreatography (ERCP) and surgical exploration. We present the case of a 47-year-old female diagnosed with EC upon exploratory laparotomy.