CT findings of an endo-orbital osteoma producing proptosis and the optic nerve's compression

Abstract 
Osteoma is a benign bone tumour, with an incidence of 2% of all orbital tumours. Osteomas located in orbit remain asymptomatic until they reach a size that originates mass effect signs such as exophthalmos, diplopia, and unilateral blindness.
Materials and methods. In this case, a male patient presented to the emergency room with progressive proptosis, worsening headaches, and swelling of the left anterior periorbital and frontal sinus region one year after the beginning of the symptoms.
Results. Imaging studies revealed a hyperdense mass in the left orbital floor displacing the left globe superiorly and anteriorly with the optic nerve’s compression.
Conclusion. Osteoma may represent an emergency in the long term when left untreated; it may destruct the eye due to direct pressure on the optic nerve and disturbance of the ocular blood supply.