Small echogenic renal masses: how often is computed tomography used to confirm the sonographic suspicion of angiomyolipoma?

• Published in: Urology (Ridgewood, N.J.) N.J.), 1995-09, Vol.46 (3), p.311-315
• Main Authors: Ikeda, Alvin K., Korobkin, Melvyn, Platt, Joel F., Cohan, Richard H., Ellis, James H.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Angiomyolipoma - diagnostic imaging; Biological and medical sciences; Carcinoma, Renal Cell - diagnostic imaging; Chi-Square Distribution; Diagnosis, Differential; Female; Follow-Up Studies; Humans; Investigative techniques, diagnostic techniques (general aspects); Kidney Neoplasms - diagnostic imaging; Male; Medical sciences; Middle Aged; Retrospective Studies; Tomography, X-Ray Computed; Ultrasonic investigative techniques; Ultrasonography; Urinary system
• ISSN: 0090-4295; 1527-9995
• DOI: 10.1016/S0090-4295(99)80212-X

Although renal angiomyolipoma (AML) has a typical ultrasound appearance, many authorities suggest that a computed tomography (CT) scan be obtained to confirm the diagnosis because small echogenic renal cell carcinomas can simulate AML. Our study evaluates the actual follow-up in such patients and factors that may affect whether CT confirmation is recommended or obtained. From 1986 through 1992, 36 patients had an ultrasound diagnosis of probable renal AML (well-circumscribed, homogenously echogenic mass). In each case the patient's age, symptoms, ultrasound results and recommendations, and imaging follow-up were recorded. CT confirmation of the sonographic diagnosis was recommended in only 11 of 36 (31%) patients. Only 7 of these 11 patients actually underwent CT, 5 of whom had the diagnosis confirmed by CT detection of intratumoral fat. Ten of 23 patients (43%) over 50 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 23 (26%) smaller masses. None of the 9 patients under age 50 years with small masses (less than 10 mm) had CT recommended. Although many authorities recommend CT to confirm the sonographic diagnosis of renal AML, this algorithm is rarely followed in everyday clinical practice, especially in patients under age 50 years with masses less than 10 mm.