Acoustic Schwannoma. In NF2, patients develop bilateral acoustic schwannomas, along with spinal cord ependymomas, and multiple meningiomas.
Neurofibromatosis, Type 2
Genetics
Incidence of ~ 1/30,000 (think: one-tenth as common as NF-1*)
- 50% of cases are Autosomal Dominant inherited, the remainder are spontaneous.
- NF2 gene mutation is on chromosome 22 and affects a cytoskeleton protein, merlin, which regulates receptor signaling.
- Mnemonic: NF2 mutation is on chromosome22.
Tumors
- Bilateral acoustic schwannomas (8th nerve tumors)
- Bilateral acoustic schwannomas are diagnostic of NF-2.
- Meningiomas
- Multiple meningiomas are characteristic of NF-2.
- By the 7th decade, > 75% of patients will have a meningioma.
- Ependymomas of the spinal cord
- The most common adult-onset intramedullary spinal cord tumor is ependymoma.
Nonneoplastic lesions
- Nodular ingrowth into the spinal cord (schwannosis)
- Meningeal cell and blood vessel proliferation into the brain (meingoangiomatosis)
- Juvenile cataracts
References
Image Reference
- Acoustic Schwannoma.
- Image from MBq, Selbsterstellt, Germany