Renal puncture. A neglected aid in the diagnosis of renal masses.

Renal arteriography and nephrotomography are useful in distinguishing between renal neoplasmas and cysts. In the great majority of cases the well-vascularized neoplasm is readily identified. However, the arteriographic diagnosis of an "avascular lesion" is incomplete. These lesions make up a widely heterogeneous group, including the common simple renal cysts, avascular and degenerated neoplasms and congenital malformations. Percutaneous puncture of these "avascular" lesions under image-amplified fluoroscopy is a safe and simple means of obtaining further diagnostic information, often of decisive value.