Rare Primary Osseous Kaposiform Hemangioendothelioma Treated with Maternal Fibular Allograft: A Case Report and Review

Abstract

Kaposiform hemangioendothelioma (KHE) is a rare vascular tumour of intermediate malignancy, with primary osseous involvement being exceptionally uncommon. The first case from India of femoral diaphyseal KHE in a 3-year-old boy who presented with recurrent fractures and thigh swelling was reported. The MRI was suggestive of a T2 hyperintense soft tissue mass in the mid-diaphysis of the right femur with multiple hypointense foci within. Diagnosis was confirmed by histopathology and immunohistochemistry. The patient underwent wide excision of the femoral diaphysis with maternal fibular allograft reconstruction. At 11 months, graft displacement and non-union required revision surgery with a second maternal fibular strut, after which stable function was achieved. Femoral diaphysis was removed, preserving 3 cm proximal and 2 cm distal femur, and a maternal non-vascularized fibular allograft was used for bony reconstruction with two plates and screw fixation. The post-op period was uneventful. Since KHE may regress over time, conservative management is an option if symptoms are controlled and limb salvage is not possible. Further studies are necessary to validate these approaches and establish standardised treatment protocols. This case demonstrates the feasibility of maternal fibular allograft in pediatric bone KHE and emphasises the need for close follow-up due to graft-related complications.