A Rapidly Expanding Hemorrhagic BRAF-Mutant Orbital Atypical Glomus Tumor

Abstract

A healthy 32-year-old woman presented with the acute onset of left sided eye pain, upper eyelid fullness, and binocular diplopia during light weightlifting. Examination elevated intraocular pressure, proptosis, upper eyelid ptosis, and motility deficits. CT demonstrated a well-circumscribed, homogeneous-appearing extraconal mass in the superior left orbit. The patient underwent an urgent orbitotomy with the excision of a hemorrhagic mass. Histopathology showed a glomus tumor with atypical features and hemorrhagic infarction, best classified as having uncertain malignant potential. A B-Raf proto-oncogene V600E mutation was detected with immunohistochemistry, which suggests a more aggressive tumor behavior yet presents an opportunity for targeted primary or adjunctive therapy. This is the first reported case of a B-Raf proto-oncogene-mutant atypical glomus tumor arising in the orbit.