Sino-nasal haemangiopericytoma.

Hemangiopericytomas are very rare soft tissue tumors of vascular origin featurding pericyts distributed around vascular spaces. They have unpredictable biological behavior and a high local recurrence rate. Silver reticulin stain is essential for their histologic diagnosis. Approximately one third occur in the head and neck. Metastases occurs in nearly one half of all cases. They are relatively radioresistant despite their great vascular component. Wide local excision of the lesion, whenever feasible and lifelong follow-up should be the treatment of choice.