Orbital hemangiopericytoma: case report of a long-term recurrency.

Among tumors concerning the orbit, hemangiopericytoma is one of the most unusual forms. This tumor has a vascular origin and usually appears as a fleshy, well-circumscribed mass, characterized by slow growth and lack of soreness. Its biological traits include a mostly benign nature, a potential malignancy, and, most of all, a highly frequent recidivation. This study of double recidivation shows this can occur even after a long lapse of time and the new tissue can acquire malignant traits. Finally, we describe the modes of the surgical approach, which aims at intervening the most radical cases to reduce recidivation to a minimum.