Neuroimaging findings of extensive sphenoethmoidal dysplasia in NF1

Abstract

Whereas isolated sphenoid wing dysplasia (SWD) is a well-known clinical feature in neurofibromatosis 1 (NF1), extensive cranial defects involving multiple bones have been rarely reported in this disorder. In this report, we describe the clinical course of a 20-year-old male with NF1 and an extensive cranial bone dysplasia. The large sphenoethmoidal defect was associated with transethmoidal and orbital cephalocele as well as inferolateral herniation of the frontal lobe. In spite of the large defect, the individual did not have any symptoms or complications resulting from the osteopathy. We review the current knowledge of the pathogenesis and management of cranial bone dysplasia in NF1.

Keywords: Neurofibromatosis type 1; Sphenoethmoidal defect; Sphenoid wing dysplasia.

Figure 1

Two cranial CT scans and 1 coronal MRI reveal extensive bone dysplasias. Panel A: An axial brain CT reveals absence of the right greater wing of the sphenoid bone marking the lateral wall of the orbit and the posterior and middle ethmoid air cells. Panel B: A coronal face CT shows the absence of the superior and medial right orbital walls. The anterior cranial fossa contents are herniating through the defect and are in communication with orbital contents. Panel C: Non-contrast, coronal T1 MR image demonstrating prolapse of anterior cranial fossa contents. There is also development of a small arachnoid cyst from expansion of the subarachnoid space.