Head and neck hemangiopericytoma.

Hemangiopericytomas are rare tumors of vascular origin featuring pericytes distributed about vascular spaces. Silver reticulin stain is essential to their histologic diagnosis. Approximately one third occur in the head and neck. Metastases occur in nearly one half of all cases and late local recurrences are common They are relatively radioresistant despite their great vascular component. The recognized treatment is therefore wide local excision and lifelong follow-up. Forty-two previously reported cases are tabulated and three new cases are presented. The occurrence of this lesion in the larynx is described for the first time.