Treatment of cystic hygroma in a young infant through multidisciplinary approach involving sirolimus, sclerotherapy, and debulking surgery

CH: cystic hygromas EXIT: extrauterine intrapartum airway intervention MRI: magnetic resonance imaging mTOR: mammalian target of rapamycin INTRODUCTION Cystic hygromas are macrocystic lymphatic malformations that develop during the sixth gestational week. Cystic hygromas (CH) mostly present in the neck and comprise 20% to 25% of cervical lymphatic tumors. Mainstay treatment of CH involves complete surgical resection and sclerotherapy. Sclerotherapy has been consistently chosen over the other modalities. Oosthuizen et al reported a management algorithm that incorporated sclerotherapy and surgery in the management of cervicofacial lymphatic malformation. Sclerotherapy has been consistently employed in the management of lymphatic malformations with notable reduction (30%) and sometimes complete eradication of cystic hygrma. Intralesional bleomycin helped achieve complete clinical remission in 47% of patients, greater than 50% reduction in 35.8%, and less than 50% reduction in 17.1% in a 70-patient trial. However, sclerotherapy has many adverse effects including swelling at the site of the lesion, scarring, pulmonary fibrosis, hemorrhage, and infection. Additionally, sclerotherapy may be futile in the management of cysts not accessible for injections. Therefore, we propose a more effective approach that involves combining sirolimus to the aforementioned modalities. Sirolimus inhibits mammalian target of rapamycin (mTOR). Specifically, sirolimus binds to FK506 to form a protein complex that avidly binds to mTOR resulting