A case of obstructive jaundice due to autoimmune pancreatitis and a review of the literature.

A 33-year-old man presented with jaundice, mild pancreatitis, and some weight loss. Laboratory tests showed cholestatic icterus. Imaging revealed distal bile duct obstruction and a mass in the head of the pancreas suspicious for cancer. Besides the enlargement of the head, the whole pancreatic parenchyma was altered. Therefore, autoimmune pancreatitis was considered. Endoscopic ultrasound biopsy found pancreatic tissue with lymphoplasmacytic inflammation and fibrosis. IgG4 serum concentration was within normal range. Due to the benign histology, a therapeutic attempt with prednisolone was initiated. The radiologic changes improved within 2 weeks, which supported the diagnosis of autoimmune pancreatitis. Bile duct obstruction and radiologic abnormalities of the pancreas completely resolved after a 4-month course of steroid treatment. Within 10 months, no relapse occurred. In context with this case, the recent literature was reviewed and the international consensus diagnostic criteria for autoimmune pancreatitis are summarized.