Idiopathic retroperitoneal fibrosis with duodenal obstruction successfully treated with corticosteroids

We report a case of idiopathic retroperitoneal fibrosis presenting with duodenal obstruction. A 55-year-old man suddenly developed severe epigastric pain and was admitted to our hospital. On abdominal computed tomography (CT), a large retroperitoneal mass was found. Hypotonic duodenography showed obstruction of the third portion of the duodenum. He was diagnosed as idiopathic retroperitoneal fibrosis and was treated with prednisolone. The patient improved dramatically. He has been well for twelve months without any further treatment.