Peripheral Solitary Osteoma of the Zygomatic Arch: A Case Report and Literature Review.

Osteoma is a benign slow-growing osteogenic neoplasm commonly occurring in the craniofacial skeleton, characterized by the proliferation of compact and/or cancellous bone. Osteomas may be peripheral, central, or extraskeletal. Peripheral osteomas arise from the periosteum and are quite uncommon in the jaw bones. The exact aetiology and pathogenesis of peripheral osteoma are unknown. Clinically, peripheral osteomas are usually asymptomatic, but depending on the location and size of the lesion, it may cause swelling, pain, esthetic disfigurement and functional impairment. On radiological imaging, a peripheral osteoma appears often as well-circumscribed, round to oval, pedunculated radiopaque mass attached to the cortex by a broad base or a pedicle. Asymptomatic osteomas are treated conservatively, while surgical excision is indicated when the lesion is symptomatic, actively growing, or for cosmetic reasons. Histologically, osteomas are composed of a normal-appearing, dense mass of lamellar bone. Recurrence of peripheral osteoma after surgical removal is extremely rare and there are no reports of malignant transformation. A review of the literature disclosed only 7 well-documented cases of peripheral osteoma located at the zygomatic bone. The purpose of this article is to present the clinical, radiographic, surgical and histological features of a solitary peripheral osteoma of the left zygomatic arch in a 55-year-old woman and to review the literature about this uncommon pathologic entity.