Surgical management of angiomyolipoma - Nephron-sparing surgery for symptomatic tumour

Angiomyolipoma (AML) is a benign renal tumour that occasionally requires intervention. We evaluated the surgical management of symptomatic angiomyolipoma, with special attention to the feasibility of nephron-sparing surgery. A retrospective study was conducted enlisting 23 patients (including 3 patients with tuberous sclerosis) who had their AML treated surgically from 1991 to 1998. The study included 7 males and 16 females, with a mean age of 49 years (range 24-75). The mean tumour size was 12.3 cm (range 1.5-30.0) including 7 lesions less than or equal to 4 cm and 16 lesions >4 cm. The presenting features included abdominal/loin pain (9 patients), spontaneous rupture (5 patients), non-specific symptoms (7 patients) and incidental findings (2 patients). AML was diagnosed by computed tomography in 16 patients and malignancy was suspected in 7 patients. The latter group included 5 patients with lesions smaller than 4 cm, one of them having coexisting AML and renal cell carcinoma. All patients underwent elective surgery, with the exception of one, who required a semi-emergency operation. Nephron-sparing surgery using frozen section in 5 patients (all diagnostic) was carried out on 16 patients, including all 5 patients with previous hemorrhage and 2 patients with suspected lesions from preoperative studies. Total nephrectomy was performed in 7 patients, including the other 5 patients with lesions suspected to be malignant. There was no operative mortality. Two complications were encountered in the entire group. We conclude that elective nephron-sparing surgery is feasible, even for massive angiomyolipoma or after previous rupture, especially when the diagnosis is made by preoperative imaging and/or intraoperative frozen section.