A case of eosinophilic cholangitis without bile duct stenosis diagnosed by bile duct biopsy

Abstract

Eosinophilic cholangitis (EC) is a rare benign disease that is often misdiagnosed as a malignancy due to the development of biliary stricture. This disease is generally diagnosed by liver biopsy or surgery. Herein, we report a case of EC diagnosed in an 86-year-old Japanese woman, who presented with fever, elevated eosinophil count, and elevated liver enzyme level, based on intraductal ultrasound evaluation showing bile duct wall thickening and bile duct biopsy of the same site. We diagnosed this case as EC based on the triad of wall thickening of the biliary system, histopathological findings of eosinophilic infiltration of the biliary tract, and reversibility of biliary abnormalities without treatment. Bile duct biopsy during endoscopic retrograde cholangiopancreatography (ERCP) is rarely used to confirm the diagnosis of EC without bile duct stenosis. For EC and cholecystitis associated with eosinophilia, bile duct biopsy under ERCP, which is less invasive, should be considered. This patient was older than the previously reported patients, and the value of a minimally invasive diagnosis was high.

Keywords: bile duct; endoscopic retrograde cholangiopancreatography; eosinophilic cholangitis.

FIGURE 1

(a) Abdominal ultrasonography showing the diameter of the common bile duct was 6.3 mm (A) and the thickness of the common bile duct wall was 1.3 mm (B). (b, c) Contrast‐enhanced computed tomography of the abdomen showing enlargement and edematous thickening of the gallbladder (→) and bile duct walls (▲). The bile duct dilatation was mild, and no stones were observed. (d) Magnetic resonance cholangiopancreatography showing that the common bile duct was dilated. However, there was no dilatation and stenosis of the intrahepatic bile ducts

FIGURE 2

(a) Endoscopic retrograde cholangiopancreatography revealed no sites of stenosis. (b) Intraductal ultrasound indicated diffuse thickening (→) of the extrahepatic and intrahepatic bile ducts. (c) Bile duct biopsy was performed using small cup forceps (Boston Scientific). (d) Histopathological examination showing a collection of eosinophils in the epithelial stroma of the bile duct with no change in the epithelial structure (×400)

FIGURE 3

The image shows significant improvement in laboratory values, including eosinophil count, after biliary stent placement, indicating significant progress after the initial examination. ALP, alkaline phosphatase; ALT, alanine aminotransferase; AST, aspartate aminotransferase; γ‐GTP, γ‐glutamyl transpeptidase.