There have been only 26 cases of hypoglossal schwannomas reported to originate intradurally
and extend extradurally into the hypoglossal canal. This 31-year-old mother of two
children presented with a 5-day history of progressive headache, nausea, vomiting
and vertigo. Her neurological exam was significant for nystagmus and left tongue deviation
with marked atrophy. An initial head CT revealed extensive left hypoglossal canal
erosion with 4th ventricle compression. T1-weighted MR images with contrast revealed a 4×3 cm left cerebellopontine angle non-homogeneously
enhancing mass with an intracranial cystic component and prominent extension into
the eroded hypoglossal canal. A left lateral suboccipital craniotomy was performed
for subtotal microsurgical resection of the intradural posterior fossa mass. A schwannoma
was diagnosed after resection and gamma knife surgery (GKS) was performed three months
later for the extradural residual tumor without further deficits. This is a rare report
of a hypoglossal schwannoma in a young patient who was treated with a multimodality
approach in order to minimize risks. A review of the literature and discussion of
the respective benefits of microsurgery versus GKS and long-term follow-up issues
are presented.
hypoglossal schwannoma - lateral suboccipital approach - gamma knife surgery - stereotactic
radiosurgery
