Proptosis Reduction Using Sirolimus in a Child with an Orbital Vascular Malformation and Blue Rubber Bleb Nevus Syndrome

A 15-month-old boy with left congenital proptosis presented to the emergency department with melena. Upper GI endoscopy and magnetic resonance angiography revealed vascular lesions, consistent with gastrointestinal tract manifestations of blue rubber bleb nevus syndrome. MRI revealed vascular malformations in both orbits, with mass effect on the left side. The patient was started on a trial of the antiangiogenic agent sirolimus (also known as rapamycin), and after 6 months of treatment showed clinical improvement in proptosis supported by radiologic evidence of regression in the larger, left orbital mass, with stability of the smaller, right orbital mass. There are 11 published cases of orbital blue rubber bleb nevus syndrome in the English literature. To our knowledge, this is the first reported case of successful, long-term treatment with sirolimus causing a reduction in the size of an orbital vascular malformation.