Huge aggressive mixed-type osteoma in a young patient

We present a 14-year-old male patient who had progressive exophthalmos and deformity in the fronto-orbital region of 5 months' duration. Neurologic examination of the patient revealed limitation in upward gaze. A Waters' view X-ray revealed a dense osseous mass located in the right frontal sinus and orbit. Computed tomography revealed a bony mass extending to the right frontal sinus, orbital space, anterior ethmoid sinus, and frontal lobe. The frontal process of the maxilla, nasal bone, and crista galli were also involved. Magnetic resonance imaging demonstrated heterogeneous signal intensities in the medial part of the lesion, while the lateral part showed no signal from dense osseous tissue. The entire osseous mass was excised. Pathological investigation of the specimen revealed a mixed-type osteoma.