Autoimmune pancreatitis with retroperitoneal fibrosis which responded to steroid therapy but was complicated with refractory renal dysfunction.

A 58-year-old male had been diagnosed as having autoimmune pancreatitis (AIP) from the results of serological examinations and image findings. He was treated with prednisolone (PSL) for 3.5 months. Fifteen months later, follow-up CT revealed the main pancreatic duct (MPD) dilatation in the pancreas body to tail and right hydronephrosis caused by complicated retroperitoneal mass. We diagnosed him as having recurrent AIP with retroperitoneal fibrosis, and restarted PSL treatment. After one month, Examinations indicated amelioration of the MPD dilatation and right hydronephrosis, but not the right renal failure. This case indicates the importance of maintenance of PSL treatment.