Contemporary experience in the management of angiomyolipoma

Purpose: We review our single center experience in the management of renal angiomyolipoma (AML) in patients who were treated with active surveillance (AS) or invasive treatment protocols. Patients and Methods: A prospectively evaluated database was reviewed, and we identified 91 patients with the diagnosis of renal AML who presented between June 1985 and February 2009. Patient characteristics, clinical presentation, treatment modalities, and patient outcomes were evaluated. Patients on AS were analyzed for successful completion of the surveillance protocol considering age, symptomatic presentation, and tumor size as potential predictors of invasive treatment. Results: A total of 91 patients with AMLs were identified. The mean patient age was 57 years. Seventy-three (83.9%) patients presented incidentally, and 14 (16%) patients were symptomatic at presentation. Forty-five patients were treated with AS, 4 underwent embolization, and 38 patients had extirpative surgery. After a median follow-up of 54.8 months (range 0.2-211.7mos), there was a mean growth rate of 0.088cm/year in the group who were treated with AS. AS failed in three patients. Two patients had retroperitoneal bleeding during the observation period, and one patient manifested an expeditious growth rate of 0.7cm/year and underwent a radical nephrectomy. Conclusions: AML is a renal tumor that usually exhibits a benign course. Surgical removal and embolization are the standard invasive treatment modalities. AS for AMLs is associated with a slow and consistent growth rate (0.088cm/year), typically has minimal morbidity, and is a reasonable option in selected patients. Symptomatic presentation and size (>3cm) are not predictive for necessitating an invasive procedure.