Bone kaposiform hemangioendothelioma: A rare entity dramatically improved by sirolimus

Abstract

Kaposiform hemangioendothelioma (KHE) is a rare vascular neoplasm occurring mostly in infancy or at birth. 1 In most cases, the lesion develops in soft tissues, consisting of an ill-defined cutaneous, red to purple indurated painful tumour. It may be complicated by Kasabach-Merritt phenomenon (KMP), characterised by severe thrombocytopenia and coagulation activation and rapid enlargement of the lesion. 1,2 Contiguous partial bone involvement is frequent; however, cases of deep locations and even bone location sparing the skin are much rarer. Furthermore, late onset is described in older children, but is rare. 3,4 Atypical features may lead to diagnosis delay. We report two cases of late-onset bone KHE. Those observations illustrate the difficulties in establishing the diagnosis and highlight the dramatic efficacy of sirolimus treatment in this condition.

Case Report: Bilateral symmetrical primary kaposiform hemangioendothelioma of the femur

“…Although 62.8% of KHE patients were reported to have musculoskeletal diseases, most of the KHE lesions were deep soft tissue that invaded bones. Lesions primarily originating from bone and limited inside bone are very rare (6). Among a series of 31 KHE patients, Kuo et al reported that there were six primary bone KHE cases involving the unilateral limb bones, spine, sacrum, scapula, and sternum (3).…”