Angiomyolipoma: Ultrasonic-pathologic correlation

Previous reports of angiomyolipoma have emphasized the ultrasonic finding of a very echogenic intrarenal mass. Ten cases of angiomyolipoma for which ultrasound examinations were available were retrospectively reviewed and correlated with their pathologic findings, and, when available, with computer tomographic findings to determine if other sonographic patterns could be recognized. In addition to the typical echodense pattern (six cases), a mixed pattern (two cases) and a low sonodense pattern (two cases) were discovered. To determine if typical echodense pattern is specific for angiomyolipoma, 42 cases of renal cell carcinoma for which ultrasound examinations were available were also retrospectively reviewed. In two cases of renal cell carcinoma echodense patterns that were indistinguishable from those of angiomyolipoma were found. Two conclusions are reached: (a) there is a spectrum of ultrasonic findings with angiomyolipoma, and (b) the presence of an echodense intrarenal mass, although very suggestive of angiomyolipoma, is not pathognomonic.