Retroperitoneal fibrosis associated with membranous nephropathy effectively treated with steroids.

Corticosteroids were successfully used to treat a 66-year-old man with retroperitoneal fibrosis (RPF) and previously diagnosed membranous nephropathy. Proteinuria was noted at the age of 51 years, and membranous nephropathy was diagnosed by renal biopsy. Ten years later, he presented with right hydronephrosis and renal dysfunction, and was diagnosed as having RPF based on the typical diagnostic imaging findings. Steroid therapy was successful, resulting in improvement of the hydronephrosis and renal function. The hydronephrosis recurred three years later, but corticosteroids were again effective in improving ureteral obstruction. This was a rare case of recurrent RPF with membranous nephropathy in which steroid therapy was effective in treating pleural effusion and hypergammaglobulinemia during the clinical course. This case suggests that an immunological disorder is involved in the pathogenesis of RPF.