Eosinophilic Cholangitis--A Challenging Diagnosis of Benign Biliary Stricture: A Case Report.

When confronting a biliary stricture, both benign and malignant etiologies must be carefully considered as a variety of benign biliary strictures can masquerade as hilar cholangiocarcinoma (CCA). Therefore, patients could undergo a major surgery despite the possibility of a benign biliary disease. Approximately 15% to 24% of patients undergoing surgical resection for suspected biliary malignancy will have benign pathology. Eosinophilic cholangitis (EC) is a rare benign disorder of the biliary tract, which can cause obstructive jaundice and can pose a difficult diagnostic task. We present a rare case of a young woman who was referred to our hospital with obstructive painless jaundice due to a biliary stricture at the confluence of the hepatic bile ducts, with a provisional diagnosis of cholangiocarcinoma. Though, during her work up she was found to have EC, an extremely rare benign cause of biliary stricture, which is characterized by a dense eosinophilic infiltration of the biliary tree causing stricturing, fibrosis, and obstruction and which is reversible with short-term high-dose steroids. Despite its rarity, EC should be taken into consideration when imaging modalities demonstrate a biliary stricture, especially if preoperative diagnosis of malignancy cannot be made, in the setting of peripheral eosinophilia and the absence of cardinal symptoms of malignancy.