| Abstract: | Since venous collaterals were described in 1981 as causing linear densities in the perirenal fat, the list of causes of perirenal cobwebs has continued to grow. Inflammatory and neoplastic processes, particularly those originating in the kidney, may produce similar appearances. If no cause for the cobwebs is found in the kidney, extrarenal pathology should be considered, in particular acute pancreatitis and aortic aneurysm rupture. Four patients are described who all demonstrated unilateral perirenal cobwebs in association with ruptured abdominal aortic aneurysms. It is postulated that blood enters the perinephric fat through weak points in the renal fascia caused by the entrance of vessels. |
