Malignant Hemangioendothelioma of Occipital Bone

Epithelioid hemangioendothelioma is a rare vascular tumor of bone, and rarely these lesions can present as unique
and extremely aggressive tumor. We report a case of highly aggressive epithelioid hemangioendothelioma and discuss the
imaging findings. CT brain plain study revealed a poorly-defined, mixed density expansile and lytic lesion involving the
occipital bone with extension to the left side with poorly defined trabecula formation. There was significant but irregular
enhancement after intravenous administration of contrast material and also marked bone destruction. Microscopic
examination of the fine needle aspiration cytology showed a tumor composed of vascular channels lined by plump
endothelial cells, which had enlarged hyperchromatic nuclei. In view of the extensive infiltration the patient was submitted
for the radiotherapy.