36 - Sirolimus as Salvage Therapy for Recurrent Fibroadipose Vascular Anomaly
R. T. Le, A. Majumdar, C. Johnson
Purpose: Fibro-adipose vascular anomaly (FAVA) is a recently described complex vascular malformation associated with PIK-3CA mutation, commonly affecting the extremities, and resulting in debilitating pain and reduced mobility in otherwise healthy children. Management is focused on alleviating patient symptoms. Surgery is the only established potentially curative option but is generally a last resort to spare patients from morbidity or limb loss, especially if effective interventional procedures (e.g. sclerotherapy, cryoablation) have not been attempted. Systemic medical management has been considered for cases refractory to localized treatment, which includes the off-label use of sirolimus, an mTOR inhibitor typically used for oncologic tumors, lymphatic malformations, and renal transplant rejection prevention. We report two cases of recurrent FAVA in which treatment with sirolimus resulted in dramatic reduction of pain and improved quality of life.
Material and Methods: Patient A initially presented with right gluteal pain secondary to a mass with classic imaging characteristics of FAVA. Management with sclerotherapy was complicated with sclerosant extravasation, resulting in soft tissue ulceration and necrosis, and requiring multiple surgical debridements. Sclerotherapy provided symptom relief for four years. However, when the FAVA lesion recurred in the same location, the patient opted for sirolimus given previous sclerotherapy complications. Patient B presented with difficulties walking secondary to a right leg mass, with classic imaging characteristics compatible with FAVA. She was treated with sclerotherapy, which resulted in persistent pain and paradoxical increase in lesion size. Patient was subsequently started on sirolimus, which she took for over two years.
Results: Both patients tolerated medical therapy, noting a reduction in the tumor burden and pain, allowing them to maintain their quality of lives. Patient A did not report any adverse reactions to sirolimus, Patient B experienced mucositis one month after treatment initiation which self-resolved with supportive care.
Conclusions: Sirolimus can be effective in ameliorating pain for recurrent FAVA lesions that were not amenable to definitive initial interventions.