Hemangioendotheliomas, along with hemangiopericytomas and angiosarcomas, are tumors that arise from vascular structures. In the case of hemangioendotheliomas, the cell of origin is the endothelial cell, and they range from benign to frankly malignant lesions.
They typically occur in young patients.
They occur especially in the soft tissues of the limbs and are often closely related to veins, from which they are thought to arise.
Less frequently they can arise in bone (osseous hemangioendothelioma), in which case they are most often seen in the calvaria, spine or lower limbs.
Nonspecific soft tissue mass. When involving bone, they are predominantly lytic, and may mimic hemangiomas with a coarse honeycomb appearance.
Dense, well-circumscribed areas of enhancement with early draining veins and shunting. Hemangiopericytomas are described as having a pedicle formed by the arteries supplying the tumor from which vessels branch to encircle the tumor.
Non specific soft tissue mass, with density similar to muscle but demonstrating bright contrast enhancement. CTA may demonstrate large feeding vessels.
Brightly enhancing soft tissue mass, often hyperintense on T2WI, with prominent flow voids, most marked in hemangiopericytomas.