Autoimmune pancreatitis presenting as a pancreatic mass mimicking malignancy.

Autoimmune pancreatitis is a rare cause of chronic pancreatitis and pancreatic mass. We describe a case of focal autoimmune pancreatitis in a 51-year-old man presenting with obstructive jaundice and pancreatic mass, mimicking malignancy. The immunological test was suggestive of autoimmune pancreatitis, and the patient responded well to a course of steroids, with complete resolution of the pancreatic mass. Autoimmune pancreatitis, therefore, must be kept in mind as a differential diagnosis of pancreatic mass. Recognition of this disease by its typical radiological and serological findings may help to avoid unnecessary surgical resection.