Orbital neuromuscular choristoma of the ophthalmic nerve

Neuromuscular choristoma (NC) is a rare tumor composed of striated muscle fibers admixed with nerve fibers that often affects large peripheral nerve trunks in children. To the best of our knowledge, this is the first reported case in the literature of a NC of the ophthalmic nerve in an adult.

A 27-year-old woman presented with a 20-day history of left periorbital headache radiating to the frontotemporal region, with associated tearing, nausea, and vomiting. The examination was normal, except for hypoesthesia in the distribution of the first trigeminal nerve branch (V1). Cranial computerized tomography showed a lesion in the left orbit and cavernous sinus with widening of the superior orbital fissure. On magnetic resonance imaging, the lesion was well-defined with fusiform morphology and showed a central cystic component and peripheral enhancement. An extradural approach was performed with subtotal tumor resection. Biopsy showed proliferation of striated muscle cells admixed with nerve fascicles and Schwann cells. A pathological diagnosis of NC of V1 was determined. Six months after surgery, left hypotropia with limitation of supraduction was observed, as well as hypoesthesia and paralysis of the left forehead with ipsilateral eyebrow ptosis. The rest of the examination remained within normal limits.

NC should be considered in the differential diagnosis of a young patient with periorbital headache and hypoesthesia in the V1 region.