Extrarenal abnormalities in Tc-99m DTPA renal perfusion studies due to hypervascularized tumors.

In cases of impaired renal perfusion and/or function, Tc-99m DTPA renal flow studies are often used as screening procedures. Besides the demonstration of pathological changes in renal perfusion and/or function, various extrarenal abnormalities may sometimes be detected. Three cases of hypervascular tumors were detected during the course of Tc-99m DTPA renography. These findings stimulated further diagnostic clarification revealing extended extrarenal lesions associated with several different etiologies: angiomyolipoma in tuberous sclerosis, extramedullary manifestations of plasma-cytoma, and metastasis of renal carcinoma. One should be aware of these extrarenal abnormalities in renal flow studies since these three tumor entities frequently exhibit increased vascularity.