[Autoimmune pancreatitis: case report.].

Autoimmune pancreatitis represents a chronic inflammatory pancreatic disease with distinct clinical, morphologic and histopathological features. We report the case of a 64 year old man with obstructive jaundice in whom the imaging studies showed diffuse enlargement of the pancreas, and a mass in its head. Fine needle aspiration biopsy of the mass guided by endoscopic ultrasound showed lymphocytic infiltration and fibrosis. The size of the pancreas, laboratory abnormalities, and clinical manifestations subsided promptly after treatment with steroids. Autoimmune pancreatitis should be included in the differential diagnosis of patients with obstructive jaundice and/or pancreatic masses.