There is a paramedian frontal encephalocele and a soft tissue cleft that passes medial to an intact eyebrow. The frontal bone shows a paramedian bony cleft with an associated encephalocele. The olfactory groove, cribriform plate, and ethmoid sinus are all increased in transverse diameter, resulting in hypertelorism. The cleft extends medially to the undisturbed eyebrow to end in a short paramedian frontal widow's peak. The bony cleft begins in the region of the nasal bone and extends superiorly through the full height of the frontal bone. Posteriorly, the cleft extends through the cribriform plate and ethmoid sinus as far as the lesser wing and body of the sphenoid. The pterygoid processes are anatomically normal, but they are displaced laterally from the midline on the cleft side. There is orbital hypertelorism below and asymmetry of the floor of the anterior cranial fossa above. [from
HPO]