RENAL ANGIOMYOLIPOMA - OPTIMAL TREATMENT BASED ON SIZE AND SYMPTOMS

The natural history of renal angiomyolipoma is not well delineated. Cu rrent management options include observation, embolization, and partia l or total nephrectomy. Recommendations for treatment are usually base d on the patient's symptoms or the size of the lesion. In an effort to help define the optimal treatment of renal angiomyolipomas, we review ed our experience over the last 10 years with these tumors. We perform ed a retrospective study of 37 patients (48 renal units) diagnosed wit h renal angiomyolipoma over a ten year period at our medical center (m ean follow-up 40 months, range 1 month -12 years), Lesions were classi fied as small (<4 cm), medium (4-8 cm) or large (>8 cm) based on the s ingle largest lesion in each kidney. The relationship between the size , symptoms and treatment was reviewed. Patients were also analyzed wit h regard to the diagnosis of tuberous sclerosis. Our findings indicate renal angiomyolipomas less than 4 cm (21/37 patients) tend to be asym ptomatic and generally do not require intervention. Angiomyolipomas gr eater than 8 cm were responsible for significant morbidity and general ly require treatment (5/6). Patients with tuberous sclerosis made up o ne half (3/6) of the large lesions. Medium-sized lesions had a less pr edictable natural history, with 54% (7/13) requiring intervention to t reat hemorrhagic complications. Small asymptomatic lesions (<4 cm) ten d to remain stable but should be periodically evaluated. Medium-sized lesions (4-8 cm) have the most variable behavior. These lesions should be followed closely with serial imaging studies, and if significant c hanges in size or symptoms are noted, or the patient is at risk for fl ank trauma, elective intervention should be initiated promptly to incr ease the chances of renal salvage. Large asymptomatic angiomyolipomas (>8 cm) will most likely become symptomatic and should be treated elec tively prior to the development of symptoms and potential complication s.