Primary Extraskeletal Osteosarcoma Arising from the Optic Nerve: A Rare Case Report.

Orbital location of extraskeletal osteosarcoma is extremely rare with only 4 cases reported so far in the English literature. We present the case of a 32-year-old female who presented with proptosis and complete loss of vision of the left eye. Contrast-enhanced computed tomography scan showed a densely calcified lobulated lesion in the left optic nerve showing strong enhancement. A left fronto-occipito-zygomatic osteotomy was conducted and a greyish brown tumor was identified. Histopathological and immunohistochemical examination of the curetted material revealed it to be extraskeletal osteosarcoma. A left partial maxillectomy with ethmoidectomy and left orbital exenteration was done and the patient was advised chemotherapy with radiotherapy.