Angiomyolipomata: challenges, solutions, and future prospects based on over 100 cases treated

To examine the presentation, management and outcomes of patients with renal angiomyolipoma (AML) over a period of 10 years, at St George's Hospital, London, UK.

We assessed retrospectively 102 patients (median follow-up 4 years) at our centre; 70 had tuberous sclerosis complex (TSC; median tumour size 3.5 cm) and the other 32 were sporadic (median tumour size 1.2 cm). Data were gathered from several sources, including radiology and clinical genetics databases. The 77 patients with stable disease were followed up with surveillance imaging, and 25 received interventions, some more than one. Indications for intervention included spontaneous life-threatening haemorrhage, large AML (10-20 cm), pain and visceral compressive symptoms.

Selective arterial embolization (SAE) was performed in 19 patients; 10 received operative management and four had a radiofrequency ablation (RFA). SAE was effective in controlling haemorrhage from AMLs in the acute setting (six) but some patients required further intervention (four) and there was a significant complication rate. The reduction in tumour volume was only modest (28%). No complications occurred after surgery (median follow-up 5.5 years) or RFA (median follow-up 9 months). One patient was entered into a trial and treated with sirolimus (rapamycin).

The management of AML is both complex and challenging, especially in those with TSC, where tumours are usually larger and multiple. Although SAE was effective at controlling haemorrhage in the acute setting it was deemed to be of limited value in the longer term management of these tumours. Thus novel techniques such as focused ablation and pharmacological therapies including the use of anti-angiogenic molecules and mTOR inhibitors, which might prove to be safer and equally effective, should be further explored.