IgG4-Related Sclerosing Cholangitis Presenting as Klatskin Tumour: A Diagnostic Dilemma - A Case Report and Literature Review

Background: IgG4-related sclerosing cholangitis (IgG4-SC) is benign inflammatory disorder that causes sclerosis and fibrosis of the biliary system.It is characterized by elevation of IgG4 serum levels.Usually, IgG4-SC is associated with autoimmune pancreatitis.Differentiation of IgG4-SC primary sclerosing cholangitis and cholangiocarcinoma (CCA) is difficult, but is of utmost important for management of these patients . Case presentation:We report the case of a 71 years old gentleman who presented with obstructive jaundice.He had been diagnosed from imaging to have Klatskin type IV tumor and the plan was made for operative intervention as per the diagnosis.However, the patient wanted to sought second opinion where they diagnosed him as IgG4-SC by IgG4 level serum was found elevated.After treatment with steroids, the patient's jaundice improved.Conclusions: Surgeons should be aware about IgG4-SC characteristics and how to differentiate Cholangiocarcinoma diagonally from Primary sclerosing cholangitis.