Natural history of angiomyolipoma in lymphangioleiomyomatosis: implications for screening and surveillance

BACKGROUND: LAM is a rare disease of women categorised by lung cysts and lymphatic abnormalities. The disease occurs sporadically or associated with Tuberous Sclerosis Complex (TSC-LAM). Angiomyolipoma, a benign tumour, prone to haemorrhage, occurs mostly in the kidneys in many of these patients. Treatment guidelines exist for angiomyolipoma in patients with TSC but the natural history of angiomyolipoma in sporadic LAM has not been studied. AIMS: To document the natural history of angiomyolipoma in a national cohort of patients with sporadic LAM to inform tumour screening and surveillance protocols. METHODS: Demographic data, clinical features, lung function and tumour size were obtained from clinical records of patients attending the National Centre for LAM in Nottingham, UK. RESULTS: 122 patients with definite or probable LAM by European Respiratory Society criteria were identified. One hundred and seven had sporadic LAM, of which 53 (50%) had at least one angiomyolipoma. In patients with sporadic LAM presentation of angiomyolipoma preceded or followed onset of lung symptoms by up to 11 and 38 years respectively. Mean tumour size was 28 mm (range 5-140 mm) at presentation and growth was 1.8 mm/yr (95% C.I. 0.42-3.82) thereafter. Eleven patients with sporadic LAM had had a nephrectomy due to angiomyolipoma bleeding. The need for intervention did not differ between those with TSC-LAM and sporadic LAM. CONCLUSIONS: Patients with LAM have a high prevalence of symptomatic angiomyolipoma which can present at any time. Angiomyolipoma in sporadic-LAM have a similar risk of bleeding to those with TSC. All patients should be screened for angiomyolipoma at diagnosis of lung disease by MRI scanning and the tumours require continuous monitoring.