Multifocal kaposiform haemangioendothelioma: Another sirolimus success story

Abstract

Kaposiform haemangioendothelioma (KHE) is a rare, infiltrative, vascular tumour of infancy and early childhood that is often complicated by the Kasabach-Merritt phenomenon (KMP), a consumptive coagulopathy. We describe the case of a 7-year-old boy who presented with a left shoulder mass, splenic hypodensities, bony lesions, and a coagulopathy. The histopathological findings were consistent with KHE. Emergent treatment of KHE involves correction of the coagulopathy with blood products, while pharmacotherapy is aimed at reducing the tumour size. Emerging data suggest a role for mammalian target of rapamycin (mTOR)-inhibitors, e.g. sirolimus, in the treatment of progressive KHE, to which our patient had an excellent clinical response. Our recommendation is that KHE should be considered in the differential diagnoses of an ill-defined, infiltrating, soft-tissue mass. Pharmacotherapy including an mTOR-inhibitor should be instituted in patients with symptomatic KHE. Long-term follow-up of residual KHE lesions is essential as they follow an unpredictable course.