Lymphatic Malformation in Newborns as the First Sign of Diffuse Lymphangiomatosis: Successful Treatment with Sirolimus.

Cystic hygroma and lymphangioma, currently defined as 'lymphatic malformations', are developmental abnormalities of the lymphoid system with potential for rapid expansion. The management of these abnormalities depends on the site and extent of the lesion. A different disease is diffuse lymphangiomatosis. It is very rare at birth and its treatment remains controversial. A lymphatic malformation (cystic hygroma) of the neck of a newborn girl as the first sign of diffuse lymphangiomatosis and treatment of the latter condition with sirolimus are presented. A newborn girl with a presumed isolated lymphatic malformation of the neck and significant respiratory involvement was diagnosed via total-body nuclear magnetic resonance imaging to be affected by diffuse lymphangiomatosis; she was treated with sirolimus. The treatment with sirolimus was found to be very effective, with complete resolution of the disease, good tolerability, and no side effects. This report suggests the need to explore the possibility of diffuse lymphangiomatosis in neonates with apparently isolated lymphatic malformations. In the presence of clinical deterioration, sirolimus treatment may achieve excellent results with no adverse events.