Dayanand Kumar R 1 , Ramya Devaraj

PRESENTATION OF CASE We are reporting a case of left intraorbital abducens nerve schwannoma in a 42-year-old male patient who presented with discomfort and proptosis of the left eye of 5 months duration. He underwent imaging in the Radiology Department of MVJ Medical College and Research Hospital, Hoskote, Bangalore, and was found to have a mass lesion in the intraconal compartment of the left orbit, which involved the abducens nerve. The tumour was excised by lateral orbitotomy and histopathological examination of the operated specimen was suggestive of schwannoma. Intraorbital schwannoma is a rare tumour and accounts for about 1-2% of all neoplasms of the orbit. Orbital schwannomas most common origin is from the sensory branches of the trigeminal nerve. But, intraorbital abducens nerve schwannomas are extremely rare. Schwannomas are tumours arising from Schwann cells of the neural sheaths of motor and sensory nerves. They arise focally from the sheath of the fascicle and present as well-defined, eccentrically-placed masses.1 Three clinical forms may present- localised schwannoma in association with neurofibromatosis (as part of von Recklinghausen syndrome) or as schwannomatosis.2 Schwannoma is seen predominantly in cranial nerve VIII. Intraorbital schwannoma accounts for about 1-2% of all neoplasms of the orbit and intraconal abducens nerve schwannoma are extremely rare.3 There are less than 10 reported cases in literature. We report a case of intraorbital schwannoma arising from the terminal branch of the abducens nerve.