Kasabach-merritt syndrome in a newborn: From prenatal diagnosis with mri to treatment with sirolimus

Kasabach-Merritt Syndrome (KMS) is a rare clinical entity, found in 1% of angiomatous lesions, characterized by severe consumption coagulopathy/thrombocytopenia in association with highly aggressive neonatal vascular lesions. We describe a case of prenatally diagnosed vascular neoformation of the neck, revealed by obstetric ultrasound and then confirmed by fetal Magnetic Resonance, with subsequent onset of KMS at birth. The newborn was treated with Propanolol and Prednisone, without any benefit; Magnetic Resonance (MRI) at day 14 of life confirmed the hypervascularized lesion of about 6x7x6 cm on the right laterocervical site. Sirolimus therapy was then initiated leading to rapid improvement in thrombocytopenia and a volumetric reduction of the vascular lesion on MRI. After 12 months of treatment, MRI scan showed a further reduction in volume of the vascular lesion; also, the KMS-related thrombocytopenia was completely resolved: Sirolimus could represent the first line of treatment of vascular lesions in the neonatal age.