[Orbital neurilemmoma originated from the supraorbital nerve: case report].

The patient, 41 years old, female, was admitted to our hospital with the chief complaint of the progressively increasing painless swelling of the right eye. On examination, the right eye slightly protruded compared with the left and upward movement of the right eye was limited. Skull x-ray film (posteroanterior) showed a dome-shaped expansion in the roof of the right orbit. Orbital venogram showed inferior and medial displacement of the P1 and P2 portions and the second segment of the superior ophthalmic vein. CT scan in coronal view showed a tumor in superior par of the right orbit. Operation was performed by subfrontal approach. It was noticed that the supraorbital nerve entered the tumor. The mass, 5 g in weight, was successfully removed. Pathologically, the diagnosis of neurilemmoma was made. Postoperatively, the proptosis diminished and the ocular movements became normal in all directions. Neurilemmoma of the orbit is an uncommon tumor, accounting for only 1.7-5.6% of all orbital tumors. Identifying the original nerve of the tumor has been even rarer. Including this case, there have been only 8 individually reported descriptions. In three cases the tumor originated from the supraorbital nerve, in three cases from the ciliary nerve, in two cases from the infraorbital nerve.