Spinal cord compression through extraosseous extension of a vertebral low-grade hemangioendothelioma with histiocytoid differentiation.

Herein, we report the case of a 47-year-old man clinically presenting a slow progressive loss of lower extremity functions within 8 weeks followed by an acute neurogenic bladder dysfunction. The patient exhibited high-grade paralysis of both legs with reduced sensation from dermatome Th11 downwards as well as marked spasticity of the lower extremity. Neuroradiological examinations revealed a protruding spinal tumor with extraosseous-intraspinal extension. The resected tumor mass exhibited a highly vascularized tumor with architectural complexity and high cellularity finally leading to the diagnosis of a hemangioendothelioma. Interesting was the fact that the tumor vasculature exhibited many CD68-positive cells protruding into the lumen and, therefore, being part of a partially histiocytoid differentiation which is all the more uncommon in hemangioendothelioma. The time frame of 3 hours between embolization and tumor resection is too short to explain a monocytic intravascular reaction. Usually, hemangioendotheliomas arise from the soft tissue, lungs or liver, but intraspinal manifestations are only rarely observed. Furthermore, the clinical course with a progressive development of a paraparesis due to a hemangioendothelioma is very uncommon.