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

Abstract

Study Type – Therapy (case series) Level of Evidence 4 OBJECTIVE 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. PATIENTS AND METHODS 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. RESULTS 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). CONCLUSIONS 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.

Recent Strategies for the Management of Renal Angiomyolipoma: A Review of Diagnostic and Therapeutic Approaches

“…The first is more frequent in AMLs, whereas hematuria is associated with TSC in these patients. However, recent reports on the frequencies of such symptoms have been indicative of a general reduction in these clinical manifestations; for instance, the rate of pain was 37% to 41%, which declined to 35% over a decade in the 2010s (9,10). The characteristic feature of renal AML is thick-walled blood vessels, which do not have normal elastin and are prone to rupture (11).…”

“…Likewise, another study revealed that tumors with serial changes in volumes were associated with higher probability of hemorrhagic lesions (13). As for TSC patients, their tumors tend to be multifocal, bilateral, and larger when compared to those tumors in sporadic AMLs (10). AML in pregnant women often remains undetectable with the equivocal risk of rupture (14).…”

“…A tumor size for treatment is still enigma although some have reported a threshold around 3 to 4 cm. moreover, because most of AMLs are detected incidentally (9,10,14), decision-making for treatment is complicated, when a patient presents with a large (> 4 cm) and asymptomatic AML (14). The main aims of different treatment methods are prevention of acute events and protection of renal parenchyma in addition to the preservation of long-term kidney function.…”

“…Embolization poses a formidable challenge if AMLs are multifocal or there is a severe atheromatosis in the aorta (42). Sooriakumaran et al observed some procedure-related complications including postembolization syndrome, abscess formation, nonfunctioning kidney, and refractory hypertension derived from segmental renal infarct (10). Distinct embolic materials have been applied for AMLs such as polyvinyl alcohol, particles, gelfoam, alcohol or N-butyl cyanoacrylate, liquid ethylene vinyl alcohol copolymer, and coils (40).…”

Microwave ablation of renal tumors: state of the art and development trends

“…For benign AMLS, renal preserving treatment such as selective angioembolization and nephron-sparing surgery are preferred [37]. Thermo-ablation as RFA has also been reported to be a promising treatment for AMLs also in patients with a solitary kidney [38,39]. Considering the several theoretical advantages of microwave with respect to radiofrequencies, Zhi-yu et al [37] have proposed a study to evaluate the safety and efficacy of MWA for the treatment of sporadic renal AML.…”