Renal angiomyolipoma in Japanese tuberous sclerosis patients

Purpose Renal angiomyolipoma (AML) is a benign neoplasm that may grow massive in tuberous sclerosis (TS) patients. The aim of this study was to document the characteristics of renal AML in Japanese TS patients. Methods Medical records of 29 TS patients followed up at the authors' center were reviewed for the presence, size, symptom, and treatment of renal AML. Results Twenty-four patients screened for renal AML were subdivided into 4 groups: group 0 (n = 8), no mass; group 1 (n = 5), AML less than 1 cm in diameter; group 2 (n = 4), AML 1 to 4 cm in diameter; group 3 (n = 7), AML greater than 4 cm in diameter. When present, AML always affected both kidneys and were multiple. All patients in groups 1 and 2 were symptom free, and the tumors seemed stable in size. All tumors in group 3 grew progressively causing various symptoms. Total or partial nephrectomy or transarterial embolization was performed in 5 patients with limited success. Conclusions AML in TS patients can be stable or aggressive. Pediatric surgeons aware of this problem should be involved in a follow-up program.