Malignant hemangioendothelioma of occipital bone.

Epithelioidhemangioendothelioma 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 epithelioidhemangioendothelioma 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.