Small, asymptomatic angiomyolipomas of the kidney.

Ultrasound (US) detected 27 small, asymptomatic renal angiomyolipomas in 18 patients. Twenty-five lesions were diffusely hyperechoic and 2 were heterogeneous. Nephrotomography was positive in 8 out of 12 patients (67%), CT in 12/14 (86%), and angiography in 10/14 (71%). Percutaneous fine-needle biopsy confirmed the diagnosis in 8 out of 12 patients (67%). Nephrotomography and angiography were nonspecific, whereas CT and biopsy were most specific because of the presence of fatty tissue. Angiography helped clarify the degree of vascularity of the masses. If the diagnosis can be made preoperatively, more conservative management can be undertaken.