Extradural dumbbell schwannoma of the hypoglossal nerve: a case report with review of the literature.
BACKGROUND
Dumbbell-shaped schwannomas of the hypoglossal nerve are very rare. This report concerns a case with an extradural, dumbbell-shaped hypoglossal schwannoma extending both intra- and extracranially.


METHODS
A 25-year-old woman presented with a right hypoglossal palsy. Imaging revealed a dumbbell-shaped tumor with considerable compression and medial displacement of the medulla oblongata, diagnosed as a hypoglossal schwannoma. The tumor mass extended extracranially to the parapharyngeal space through the enlarged hypoglossal canal. The tumor was partially excised by a right far-lateral suboccipital approach and the tumor was found to be predominantly extradural with minimal intradural extension. A histopathologic diagnosis of schwannoma was made.


CONCLUSIONS
This case emphasizes the importance of recognizing this extradural variant of schwannoma. Staged extracranial and intracranial approaches to these tumors may be necessary.
Kuo
Lu-Ting
LT
Division of Neurosurgery, Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan 100.
Huang
Abel Po-Hao
AP
Kuo
Kuan-Ting
KT
Tseng
Ham-Min
HM
D000328:Adult; D003390:Cranial Nerve Neoplasms / Q000473:pathology* / Q000601:surgery*; D005260:Female; D006801:Humans; D020437:Hypoglossal Nerve Diseases / Q000473:pathology* / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008526:Medulla Oblongata / Q000473:pathology; D009442:Neurilemmoma / Q000473:pathology* / Q000601:surgery*