Cholangiocarcinoma Resembling IgG4-related Sclerosing Cholangitis

A 66-year-old man diagnosed with immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) with diffuse intrahepatic bile duct stenosis and elevated serum IgG4 levels was referred for a further examination because of elevated serum carbohydrate antigen 19-9 levels despite treatment with corticosteroids. An umbilical nodule was found on a physical examination and a biopsy showed adenocarcinoma. Although several imaging studies revealed no changes from prior studies, bile cytology collected by endoscopic retrograde cholangiopancreatography showed adenocarcinoma. Consequently, the patient was diagnosed with cholangiocarcinoma resembling IgG4-SC after detecting an umbilical metastasis, also known as Sister Mary Joseph's nodule.

Automated summary

This case report describes a patient with immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) and concurrent cholangiocarcinoma, with elevated serum IgG4 levels. The patient was diagnosed with cholangiocarcinoma after further examination and biopsy, despite no significant changes on imaging studies.