Advances in diagnostic difficulties and targeted therapy of IgG4‑related sclerosing cholangitis

IgG4⁃related sclerosing cholangitis (IgG4‑SC) is an IgG4⁃related disease charac-terized by bile duct wall thickening and luminal stricture. Its pathogenesis involves complex multi-dimensional regulation, including immune imbalance, genetic epigenetic regulation, microbial ecolo-gical abnormalities, and activation of fibrotic pathways. Due to the lack of specificity in clinical mani-festations, IgG4‑SC is easily misdiagnosed as biliary tract diseases such as cholangiocarcinoma and primary sclerosing cholangitis in the early stage, leading to diagnostic difficulties. At present, gluco-corticoids are the preferred treatment option. Although most patients can quickly recover in the early stages, high recurrence rates and hormone dependence limit the long‑term effectiveness of treatment. The authors combine the latest research progress at home and abroad to deeply analyze the pathogenesis, clinical manifestations, and diagnosis of IgG4‑SC, focusing on treatment strategies and cutting‑edge advances, in order to provide reference and inspiration for clinical practice.