S1726 Eosinophilic Infiltration Causing Biliary Tree Obstruction Without Stricture

Abstract

Introduction: We present an exceedingly rare case of eosinophilic cholangitis (EC) without stricture. Of the 40 cases of EC reported in the literature, fewer than 10 cases did not involve a stricture. Case Description/Methods: A 60-year-old female with no significant past medical history presented with symptoms of biliary colic for 2 days. Laboratory results were significant for elevated hepatobiliary enzymes including alkaline phosphatase of 300 IU/L and total bilirubin of 3.8 mg/dL. A hepatobiliary iminodiacetic acid scan was performed with an absence of radiotracer excretion into the biliary tract. However, a magnetic resonance cholangiopancreatography showed no obstructing stone, stricture, or lesion. A broad workup including hepatitis and autoimmune serologies was negative. The patient underwent an uncomplicated laparoscopic cholecystectomy, and direct inspection of the gallbladder confirmed significant edema. Histopathology of the gallbladder showed acute and chronic acalculous cholecystitis with eosinophilic rich infiltrates. Notably, the patient had an absolute eosinophil count of 1.2 cells/µL. She was diagnosed with eosinophilic cholangitis and treated with corticosteroids. At her one-month follow-up, her symptoms had resolved. Discussion: Eosinophilic cholangitis is a rare, self-limiting condition featuring eosinophilic invasion of the biliary tree. Laboratory values in EC reflect an obstructive process, but diagnosis is frequently delayed as both symptoms and imaging mimic multiple other biliary conditions including malignancy, primary strictures, primary sclerosing cholangitis, amongst others. Endoscopic dilation of strictures often provides a surprising diagnosis when pathology demonstrates dense infiltration of eosinophils. Although a majority of EC is associated with stricture, EC may also present with obstructive features in the absence of stricture. Likewise, peripheral eosinophilia may or may not be present. Risk factors for EC have not been established. Literature suggests that patients with pre-existing eosinophilic processes such as eosinophilic esophagitis and asthma are more likely to develop EC than the general population. There is no standard treatment, but corticosteroids have demonstrated empiric efficacy, similar to the other eosinophilic processes mentioned. Increased physician awareness of eosinophilic cholangitis will help prevent delays in diagnosis and initiation of effective medical therapy.