Idiopathic retroperitoneal fibrosis: a case of unilateral lesion.

Here we report a case of idiopathic retroperitoneal fibrosis, a unilateral case, which resulted in remission by ureterolysis with intraperitonealization. A 24-year-old female was hospitalized because of hydronephrosis. Many examinations were performed with the suspicion of malignant disease, but no apparent cause was detected. We suspected idiopathic retroperitoneal fibrosis and performed surgical exploration. The pathological diagnosis was retroperitoneal fibrosis. Ureterolysis with intraperitonealization of the ureter was performed. Six months later, marked improvement of the right hydronephrosis was observed without steroid therapy.