The pathology of head and neck tumors: vasoformative tumors, part 9A.

Tumors originating from components of the vascular system vary widely in the degree of morbidity and mortality that they incur. They all have endothelial cells as integral components of their histologic appearance. Vasoformative tumors include hemangiomas, lymphangiomas, and pyogenic granulomas, which are relatively common, and hemangiopericytomas, glomus tumors, and angiosarcomas, which are relatively uncommon. For many vasoformative tumors, including lymphogenous lesions, the head and neck is an area of predilection, and, in some instances, location in the head and neck appears to modify biologic activity.