Overlap syndrome of seronegative primary biliary cholangitis and small duct primary sclerosing cholangitis: a first case report and literature review.

Primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC), and autoimmune hepatitis (AIH) are distinct liver diseases. Cases combining PBC and PSC, are extremely rare. Here, we present a case of a 39-year-old woman with a history of colonic Crohn's disease treated with azathioprine.