Prevalence of sporadic renal angiomyolipoma: a retrospective analysis of 61,389 in- and out-patients

To calculate the prevalence, localization, and growth of sporadic angiomyolipomas and to identify the predominant sex in the largest patient population reviewed to date. Abdominal ultrasound analyses of 61,389 patients (49.7% women; 50.3% men) were consecutively collected using a PC-based, standardized documentation system from September 1999 to December 2012. The present study evaluates and presents this data. The population studied includes 270 cases of sporadic angiomyolipoma (184 females; 86 males). This represents an overall prevalence of 0.44%, with 0.60% in the female and 0.28% in the male subpopulations. Mean tumor size was 10.8 +/- A 5.8 mm. Fifty-seven percent of cases involved the right kidney and 43.0% the left kidney. Only 14 of the 270 patients presented with multiple angiomyolipomas, four of which were bilateral. Sixty-one cases were followed over a mean period of 25 months (range: 1-105 months) and showed no significant increase in tumor size during the period of observation. The analysis of 61,389 patients revealed a higher prevalence of sporadic angiomyolipoma than previously observed in smaller studies. There was a significantly higher prevalence in females than in males. Multiple and bilateral angiomyolipomas were rare, and tumor growth was marginal.