Background Neck lymphangioma is the most common lymphatic malformation of the newborn, representing about 5% of benign tumours of infancy and childhood. Due to its action on angiogenesis and cellular growth, the use of sirolimus (m-Tor inhibitor) has been proposed for treatment, as it has produced satisfactory results in some studies in children and in a few cases in neonatology.

Purpose To describe the use of sirolimus as treatment for a left laterocervical lymphangioma in a newborn.

Material and methods We report the case of a term male newborn (3.3 kg, 51 cm, 0.22 m²) with a left laterocervical mass (13 cm) diagnosed on a prenatal ultrasound. According to the neonatal cases in the literature, an oral solution of sirolimus 1 mg/mL was started at 0.8 mg/m²/day (divided into 12 hourly doses) for 10 days of life. Sirolimus plasma levels were monitored (LC/MS/MS), with a desired target of 4–8 µg/L, as well as adverse effects and the evolution of the mass.

ResultsThe first 2 months of treatment are described. On day 6, treatment was interrupted owing to high plasma levels. On day 14, sirolimus was reintroduced at a lower dose and once daily schedule (estimated elimination half-life of 33 hours, concordant with the neonatal literature). Posterior levels were correct and the dose was titrated according to them and the weight gain of the child. Regarding side effects, the patient experienced hypertriglyceridaemia and hypercholesterolaemia, with unaltered hepatic and renal functions associated with high sirolimus levels. He also had occasional nausea and vomiting that were appropriately managed. Posterior controls showed normalisation of triglycerides and cholesterol levels. From the beginning of treatment, the cervical mass showed a progressive reduction in size and a marked reduction in consistency.

Conclusion Sirolimus can be a useful option for the treatment of lymphatic malformations with few short term side effects. More data are needed to characterise the pharmacokinetics of sirolimus in the neonatal population, in order to define optimal dosing.

No conflict of interest