Orbital osteoma arising adjacent to a foreign body

A 27-year-old man sustained a blast injury to the face in April 1996, with a resultant foreign body at the right medial orbital wall. He refused to undergo surgical removal of the foreign body at that time and was discharged on oral antibiotics. Five years later, he presented because of recurrent attacks of swelling, redness, and pain at the right medial canthal area. A repeat computed tomography (CT) scan revealed fragmentation of the original orbital foreign body and an adjacent radiodense lesion that appeared to blend smoothly with the orbital bone from which it arose. This lesion was not present on the initial CT scan done 5 years earlier immediately following the blast. The patient was started on oral antibiotics and surgical exploration was carried out. Three fragments of the foreign body were removed in addition to the adjacent orbital lesion, which proved to be an ivory-type osteoma on histopathology. We briefly review previously suggested factors in the pathogenesis of osteoma and present further evidence in favor of both traumatic and infectious factors.