Renal angiomyolipoma - Experience of 20 years in Taiwan

Objective: 32 cases of renal angiomyolipoma were presented. Diagnosis, treatment and prognosis of the 32 cases were discussed. Material and methods: A total of 32 cases of renal angiomyolipoma treated at the Veterans General Hospital-Taipei between 1974 and 1994 were retrospectively reviewed. Follow-up periods ranged from 2 to 108 months (mean 43.4). Results: Of the 32 cases, 26 were female, 28 were unilateral lesions and 2 were associated with tuberous sclerosis. The tumor size averaged 6.73 cm (range 2-25). The mean age was 48.3 years. There was a typical image finding in 87.5% of the 28 unilateral tumors. Tumors larger than 4 cm had a greater incidence of symptoms (90%) and a higher nephrectomy rate (18/22). 30 cases underwent surgery including 22 nephrectomy, 1 partial nephrectomy and 7 enucleation. The nephrectomy rate decreased from 90% (9/10) to 59.1% (13/22) after 1985. Only 1 patient had a contralateral recurrence 26 months after surgery. Two cases had unusual presentations, which were perirenal capsule invasion and renal vein extension, respectively. Conclusions: Our experience with angiomyolipoma in the past 20 years showed that the advancement of imaging technology has much improved the diagnosis of this tumor. A correct diagnosis is possible in most cases before surgery. The nephrectomy rate has markedly decreased in recent years. Every effort shold be made to preserve renal tissue in the treatment of this benign tumor.