Autoimmune pancreatitis/IgG4-associated cholangitis and primary sclerosing cholangitis – Overlapping or separate diseases?

Histology from the liver hilum in a patient with complex hilar stricturing and an associated mass. A diagnosis of IgG4-associated cholangitis was made. (A) H+E showing extensive fibrous stroma, with associated plasma cell infiltrate. (B) IgG4 immunostaining showing >20 IgG4+ plasma cells per high power film.

Cholangiographic response to steroid therapy in autoimmune pancreatitis/IgG4-associated cholangitis. (A) ERCP showing complex hilar stricture with associated intrahepatic biliary stricturing in a patient with biliary obstruction and raised serum IgG4. The patient also had renal impairment, focal renal abnormalities on imaging, and an IgG4+ plasma cell renal infiltrate. (B) Repeat ERCP 3 months following commencement of oral steroid therapy. Marked improvement in hilar and intrahepatic stricturing is seen.