Fig. 4.

a) Coronal T2-weighted and b) axial post-contrast T1 fat-saturated MR images. The patient from Fig. 3 subsequently represented two years later with difficulty opening his right eye and changes in visual acuity. MRI demonstrated an enhancing mass lesion centered on the ethmoid sinuses, naso ethmoid complex and cribiform plate, which invades both orbits. There is invasion of the intraconal space of the right orbit, displacement of the right optic nerve and inferior lateral displacement of the right globe. The lesion was proven on biopsy to be an ossifying fibroma, although it behaved atypically in an invasive manner