Pancreatic mass lesion mimicking carcinoma: initial presentation of retroperitoneal fibrosis.

A 63-year-old woman with upper abdominal pain radiating to her back was admitted to the hospital, and a mass lesion was identified involving pancreatic body and tail, with peripancreatic lymph node enlargement. The patient had normal tumor marker levels, a very high erythrocyte sedimentation rate (104) and negative malignant cells in fine needle aspiration cytology. The patient underwent laparotomy and histological findings of mass were consistent with retroperitoneal fibrosis. She has been in remission after long-term steroid treatment. In the differential diagnosis of cases with pancreatic mass lesion, retroperitoneal fibrosis should also be considered.