Peer-Review Short Reports Intraorbital Abducens Nerve Schwannoma

Schwannomas are tumors arising from the Schwann cells of the neural sheath ofmotor and sensory nerves. They are seen in all cranial nerves except optic and olfactory. They are also called neurilemmomas, neurinomas, and perineural fibroblastomas (7). They arise focally from the sheath of the nerve fascicle and present as well-defined eccentrically placed masses. This allows their dissection from the underlying neural bundle (7). Three clinical settings can be distinguished: localized schwannomas, in associationwithneurofibromas (as apart of Von Recklinghausen syndrome), or as schwannomatosis. Schwannomas occur in any age group and there is no sex preference. They are seen predominantly in the VIII cranial nerve. When occurring in extracranial locations, they commonly involve the head and the neck (9), the tongue (4), the nasopharynx and the parapharyngeal space (10), and the brachial plexus (16). Literature mentions schwannomas in the gastrointestinal tract (20, 22), the psoas muscle (11, 21), and occasionally the external genitalia (14). Abducens schwannomas are rare tu