The urographic appearances in acute and chronic retroperitoneal fibrosis.

Retroperitoneal fibrosis is a disease which causes renal failure by obstruction of the ureters. The fibrosis may be benign or secondary to malignant disease. The clinical and radiological features of 30 cases have been reviewed. The symptoms are non-specific and diagnosis is often difficult. The most important features are back pain associated with a high ESR. Urography is diagnostic; the well known features are obvious dilatation of the pelvicalyceal system and ureter above the level of the obstruction. However, there is a spectrum of appearances corresponding to the duration of the disease and there may be only minimal dilatation of the pelvicalyceal system or no pelvicalyceal opacification at all. The progress of the disease is variable. Slow progress leads to chronic obstruction and chronic ill health. With more rapid progression, the patient may present with acute obstruction in anuria and, in such cases, urgent ureterolysis is necessary to conserve nephrons. Benign and malignant retroperitoneal fibrosis are often indistinguishable, clinically and radiologically, and laparotomy with biopsy is essential for diagnosis.