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Neurofibromatosis type 2 (NF2), also known as “Wishart disease” is a rare autosomal dominant neurocutaneous disorder characterized by the development of multiple central and peripheral nervous system tumors, most notably bilateral vestibular schwannomas, which are pathognomonic.

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Unlike NF1, cutaneous findings are minimal, and the primary morbidity arises from CNS tumors.
It is also known as MISME (multiple inherited schwannomas, meningiomas and ependymomas)

Legius E, Ludwine Messiaen, Wolkenstein P, et al. Revised diagnostic criteria for neurofibromatosis type 1 and Legius syndrome: an international consensus recommendation. Genetics in Medicine. 2021;23(8):1506-1513. doi:https://doi.org/10.1038/s41436-021-01170-5‌

Legius E, Ludwine Messiaen, Wolkenstein P, et al. Revised diagnostic criteria for neurofibromatosis type 1 and Legius syndrome: an international consensus recommendation. Genetics in Medicine. 2021;23(8):1506-1513. doi:https://doi.org/10.1038/s41436-021-01170-5‌

Etiopathogenesis

Genetic basis:

Feature	Description
Gene involved	NF2 gene on chromosome 22q12
Protein	Merlin (also called schwannomin) – a tumor suppressor
Inheritance	Autosomal dominant (but ~50% are de novo mutations)
Tumor predisposition	Loss of merlin function leads to uncontrolled proliferation of Schwann cells and meningeal cells

Clinical Features

System Involved	Key Manifestations
Auditory/Vestibular	Bilateral sensorineural hearing loss, tinnitus, imbalance
Cranial nerves	Facial palsy (CN VII), trigeminal neuropathy (CN V)
Spinal cord	Schwannomas or intradural extramedullary tumors, ependymomas
Eyes	Juvenile cataracts, retinal hamartomas
Skin	Few cutaneous neurofibromas, skin plaques (less common than NF1)

Diagnostic criteria

NIH & Manchester Criteria:

Diagnosis can also be mosaic NF2 if features are partial.

Major criteria	Minor tumors
1. Bilateral vestibular schwannomas (on MRI)

First-degree relative with NF2 and either: ◦ Unilateral vestibular schwannoma, or ◦ Any two of: meningioma, glioma, schwannoma, juvenile posterior subcapsular lenticular opacity | • Multiple meningiomas • Non-vestibular cranial nerve schwannomas • Spinal schwannomas • Ependymomas |

Radiology

https://youtu.be/C0_AqYlNRUE?si=I_dtS-Wv3x8fc1as

MRI Brain: