Conservative treatment of renal angiomyolipomas in patients with tuberous sclerosis

Renal angiomyolipoma (AML) associated with tuberous sclerosis (TS) presents a treatment dilemma due to multifocal tumors with a potential for significant growth and subsequent hemorrhage. We reviewed the literature and our experience with AML and TS patients to determine the long-term behavior of these lesions.

We reviewed 8 patients (16 renal units) with bilateral renal AMLs and comorbid TS. We evaluated their renal function, renal imaging, and clinical course. Patients were followed for a mean of 11.5 years (range 3.5 - 21 years).

The records of 8 patients (7 females, 1 male) with a mean age of 33.1 years (range 21 - 54) were evaluated. The mean serum creatinine of these patients at the time of diagnosis was 0.75 mg/dl (range 0.4 - 1.1). Mean serum creatinine at last follow-up was 0.83 mg/dl (range 0.6 - 1.3). The average size of the largest lesion was 13.9 cm (range: 0.5 - 28). Of the 8 patients, 6 received treatment during the course of their disease, including arterial embolization of 7 renal units in 5 symptomatic patients (2 patients needed 2 embolizations). Partial nephrectomy was performed on 2 renal units in 2 patients, and a total nephrectomy was performed in 1971 on another patient. Currently, all 8 patients have stable renal function; 4 patients are asymptomatic with regards to their lesions, while the other 4 patients report transient flank pain adequately controlled with oral analgesics (2 patients with propoxyphene plus acetaminophen 100/650 mg PO t.i.d. p.r.n., the other 2 patients with ibuprofen 600 mg PO p.r.n.). None of the patients experienced life-threatening hemorrhage or required dialysis.

Our study and a review of the literature have not revealed an obvious or quantitative risk of morbidity or mortality from renal hemorrhage directly related to AMLs of any specific size in TS patients. Due to multiple lesions and distortion of anatomy it can be difficult to distinguish individual lesions for preemptive treatment in asymptomatic patients. If size criteria alone are used, multiple treatments will be required over the course of the patient's life. Also, preemptive treatment exposes patients to iatrogenic morbidity. Consideration should be given to medical management of AMLs in TS patients with asymptomatic, slowly enlarging tumors that maintain features of an AML. Embolization, partial nephrectomy, or other ablative treatments (i.e. cryotherapy and RFA) can be reserved for symptomatic patients.