SMALL ECHOGENIC RENAL MASSES - HOW OFTEN IS COMPUTED-TOMOGRAPHY USED TO CONFIRM THE SONOGRAPHIC SUSPICION OF ANGIOMYOLIPOMA

Objectives Although renal angiomyolipoma (AML) has a typical ultrasoun d appearance, many authorities suggest that a computed tomography (CT) scan be obtained to confirm the diagnosis because small echogenic ren al cell carcinomas can simulate AML. Our study evaluates the actual fo llow-up in such patients and factors that may affect whether CT confir mation is recommended or obtained. Methods. From 1986 through 1992, 36 patients had an ultrasound diagnosis of probable renal AML [well-circ umscribed, homogenously echogenic mass). In each case the patient's ag e, symptoms, ultrasound results and recommendations, and imaging follo w-up were recorded. Results. CT confirmation of the sonographic diagno sis was recommended in only 11 of 36 (31%) patients. Only 7 of these 1 1 patients actually underwent CT, 5 of whom had the diagnosis confirme d by CT detection of intratumoral fat. Ten of 23 patients (43%) over 5 0 years of age had CT recommended, whereas only 1 of 13 (8%) patients under age 50 years did (P < 0.05). CT confirmation was recommended for 5 of 13 (38%) lesions greater than 10 mm and for 6 of 25 (26%) smalle r masses. None of the 9 patients under age 50 years with small masses (less than 10 mm) had CT recommended. Conclusions. Although many autho rities recommend CT to confirm the sonographic diagnosis of renal AML, this algorithm is rarely followed in everyday clinical practice, espe cially in patients under age 50 years with masses less than 10 mm.