Primary orbital hemangiopericytoma: an unusual cause of unilateral proptosis.

numerous orbital neoplastic and non neoplastic processes. Various mesenchymal tumours of both fibrohistiocytic and vascular origin are well-described causes. Hemangiopericytomas (HPC) are rare vascular tumours which can infrequently involve the orbit and their incidence is estimated to be 0.8% to 3% of primary orbital tumours1,2. We herein report a new case of orbital HPC revealed by unilateral proptosis in a 38-year-old man. Our aim was to highlight the clinicopathological and radiological features of this rare neoplasm with review of the current literature.