A 10-year-old boy with neurofibromatosis type 1 presents with a diffuse, thickened, S-shaped upper eyelid and a palpable pulsatile globe. The most likely finding explaining the pulsatile proptosis is:
- A Orbital meningocoele
- B Orbital varix with high flow
- C Absence or dysgenesis of the greater wing of the sphenoid ✓
- D Carotid-cavernous fistula
Correct answer: C. Absence or dysgenesis of the greater wing of the sphenoid
Explanation
In NF1, absence or dysgenesis of the greater wing of the sphenoid bone allows transmission of cerebrospinal fluid pulsations to the orbit, causing pulsatile proptosis. The S-shaped lid with plexiform neurofibroma is classic. Orbital meningocoele is not typical of NF1. Carotid-cavernous fistula presents with a bruit and chemosis, not pulsation from bony dehiscence.
Reference: Neuro-Ophthalmology (AAO Basic and Clinical Science Course), 2022-2023 ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.