Autoimmune pancreatitis complicated by an infected pseudocyst.

A 53-year-old man was admitted due to upper abdominal pain. He had been diagnosed with autoimmune pancreatitis (AIP) 4 years previously and had been taking steroids for maintenance therapy since that time. Abdominal computed tomography revealed multiple pseudocysts in the head of the pancreas and a dilated pancreatic duct with mottled calcifications around the pseudocyst. Despite the continuation of steroid therapy for 4 months, the size of the pseudocyst increased further and diffuse calcifications developed throughout the pancreas. He was readmitted due to severe abdominal pain and a high fever, and endoscopic drainage of the pancreatic pseudocyst was performed. Two months after the internal drainage, the pseudocyst disappeared and his symptoms subsided. There are few reports concerning AIP complicated by the formation of pseudocysts. We report this case to emphasize that AIP can be complicated by the development of pseudocysts with progression to chronic pancreatitis, accompanied by multiple calcifications.