A huge osteoma of paranasal sinuses with intraorbital extension presenting as diplopia.

Osteoma of the paranasal sinuses is a benign, well-defined and slow-growing tumor arising most commonly from the frontal sinus. The ethmoid and maxillary sinuses are less frequently involved. Very seldom, it may involve the orbit, usually by direct extension from the adjacent paranasal sinuses. We report a case of a huge osteoma in right ethmoid and maxillary sinuses with orbital extension that was accompanied by diplopia in a 20-year-old, previously healthy man. An external approach to the involved sinuses was utilized to remove the tumor completely after a successful maxilloethmoidectomy. The pathologic report confirmed the clinical diagnosis of osteoma. The patient fared well after surgery and his diplopia resolved without any definite cosmetic complications. No residual tumor was found during post-operative follow-up.