[Idiopathic retroperitoneal fibrosis: effectiveness of surgery combined with corticosteroid therapy].

Idiopathic retroperitoneal fibrosis (ERF) is a rare disease characterized by non-neoplastic fibroblastic and inflammatory proliferation. We describe a case of a 58-year-old man presenting with abdominal pain, weight loss and abdominal mass on clinical examination. The patient was evaluated by abdominal CT scan and magnetic resonance imaging which disclosed a periaortic soft-tissue mass with marked longitudinal extension below renal arteries origin. The diagnosis of ERF was histologically confirmed after surgical exploration and biopsies followed by extensive ablation of fibrous tissue. After 6 months of low-doses of postoperative steroid therapy retroperitoneal fibrous tissue had almost disappeared on CT examination.