A man in his fifties with abdominal pain, itching and weight loss.

BACKGROUND

Immunoglobulin G4-related disease (IgG4-RD) is a systemic disease which can potentially affect any organ system. IgG4-related sclerosing cholangitis and inflammatory pseudotumour in the hepatobiliary system is rare, but is probably underdiagnosed.

CASE PRESENTATION: We present the case of a 52-year-old male who was admitted with obstructive jaundice and weight loss. He presented with a mass lesion in the porta hepatis mimicking hilar cholangiocarcinoma. The patient underwent extended right hepatectomy with hepaticojejunostomy. Severe liver failure developed postoperatively, and the patient underwent liver transplantation. The resected specimen showed infiltration of IgG4 positive plasma cells in the liver hilum, and immunohistochemical staining demonstrated a ratio of IgG4/IgG-positive plasma cells of more than 40 %. Postoperative serological testing showed elevated levels of serum IgG4 6.0 g/L (0.03-2.01), and the CT imaging revealed chronic pancreatitis and bilateral enlargement of the submandibular glands. The patient was ultimately diagnosed with IgG4-related disease.

INTERPRETATION: It is difficult to distinguish benign bile duct strictures in the porta hepatis from hilar cholangiocarcinoma, and serum IgG4 is unreliable as a diagnostic marker due to low sensitivity and specificity. Greater awareness of IgG4-RD is needed in order to avoid surgery.