Introduction: IgG4-related sclerosing cholangitis is a rare inflammatory disease that characterized by elevated serum IgG4 levels, storiform fibrosis pattern of IgG4 positive plasma cell infiltration and dramatic response to corticosteroid administration. This poorly understood disease can cause both intra/extra hepatic biliary stenosis and thickening. In this regard, it can be misdiagnosed with other conditions including primary sclerosing cholangitis, and even cholangiocarcinoma

Methods: This retrospective cohort study designed to evaluate clinical manifestations, imaging findings and prognosis of IgG4-related sclerosing cholangitis in a tertiary referral center over two-year period. The diagnosis of IgG4-related sclerosing cholangitis was made based on Japanese criteria 2012. 18 patients with definite, probable and possible diagnosis of IgG4-related sclerosing cholangitis between January 2018 to August 2020 were included and followed for one year.

Results: Among total, 12 (66.7%) of them were male. The mean age at diagnosis was 44.61±15.18 years (range 21 to 67). The most frequent complaints were abdominal pain, icter, itching and weight loss seen in 10 (55.6%), 10 (55.6%), 9 (50%) and 5 (27.8%) of patients, respectively. Two patients presented with bowel obstruction symptoms. One of them referred with cholangitis symptoms and one misdiagnosed with post-cholecystectomy bile duct stricture. Extra hepatic bile ducts were involved in all patients and two patients had intrahepatic bile duct involvement simultaneously based on magnetic resonance cholangiopancreatography (MRCP) findings. Furthermore, half of patients had normal pancreas pattern. IgG4 level was elevated in 11 patients (61.1%) and the mean serum IgG4 concentration and CRP level were 159.55±176.16 mg/L and 23.14±27 mg/L, respectively.

Conclusion: This series presented to point out gastroenterologists to be aware of diagnosis of IgG4 related sclerosing cholangitis considering various presentations even in the presence of normal IgG4 level.