Like other renal tumors, AMLs are often discovered as incidental findings on axial imaging. Less commonly, the tumors may cause fank pain, hematuria, and a palpable abdominal mass. In rare cases, lifethreatening retroperitoneal hemorrhage may occur, a phenomenon known as Wunderlich syndrome. AMLs can often be distinguished from other renal masses using computed tomography (CT) because their fat content causes them to appear as hypoattenuating lesions (less than -20 Hounsfeld units). The presence of fat, however, is not pathognomonic for AML, since certain primary renal sarcomas (such as liposarcoma) and rare renal cell carcinomas may also contain fat. In addition, AMLs sometimes have little fat content that cannot be visualized with CT imaging.

The optimal management of an AML depends on tumor size and associated symptoms. Lesions that are more than 4 cm in diameter or that cause pain or hematuria are managed with embolization or extirpation (with a nephron-sparing technique whenever possible).