A 20-year-old man complains of increasing difficulty in hearing over the past several years. Physical examination confirms bilateral sensorineural hearing deficits. MRI discloses bilateral cerebellopontine angle tumors, consistent with schwannomas. This patient has a strong family history for benign tumors, including low-grade gliomas and meningiomas on his mother’s side of the family. Which of the following is the probable diagnosis?
Neurofibromatosis type 1
Neurofibromatosis type 2
Answer : B Neurofibromatosis type 2
Neurofibromatosis type 2 refers to a syndrome defined by bilateral tumors of the eighth cranial nerve (acoustic neuromas), and commonly, by meningiomas and gliomas.
Acoustic neuromas are intracranial schwannomas that are restricted to the eighth cranial nerve.
Some schwannomas exhibit deletions or mutations of the NF2 gene. Neurofibromatosis type 1 exhibits neurofibromas but not acoustic neuromas. None of the other choices lead to acoustic Schwannomas.