Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology
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Review Case Reports
Clinical and histopathologic features of recurrent vestibular schwannoma (acoustic neuroma) after stereotactic radiosurgery.
Stereotactic radiosurgery for vestibular schwannoma entails uncertain long-term risk of tumor recurrence and delayed cranial neuropathies. In addition, the underlying histopathologic changes to the tumor bed are not fully characterized. We seek to understand the clinical and histologic features of recurrent vestibular schwannoma after stereotactic radiation therapy. ⋯ The variable fibrosis in the cerebellopontine angle and lack of radiation changes seen histopathologically in irradiated vestibular schwannoma suggest that a uniform treatment effect was not achieved in these cases. Although all four patients with preoperative cranial neuropathies were found intraoperatively to have fibrosis in the cerebellopontine angle, excellent preservation of facial nerve anatomy and function was possible with salvage microsurgical resection. Additional analyses are needed to clarify the histopathologic and molecular characteristics associated with vestibular schwannoma growth after stereotactic radiation.