Neurofibromatosis Type 2

KEY FACTS

TERMINOLOGY

• Familial cancer syndrome

○ Multiple cranial nerve (CN) schwannomas, meningiomas,

and spinal tumors

IMAGING

• Best diagnostic clue: Bilateral vestibular schwannomas

• Multiple extraaxial tumors

○ Schwannomas of CNs and spinal nerve roots

○ Meningiomas on dural surfaces (up to 50%)

• Intraaxial tumors

○ Ependymomas in spinal cord and brainstem (6%)

• Recommendation: Use high-resolution T1 C+ FS MR

through basal cisterns to evaluate cranial nerves

TOP DIFFERENTIAL DIAGNOSES

• Schwannomatosis

• Multiple meningiomas

• Metastases

PATHOLOGY

• All neurofibromatosis type 2 (NF2) families have

chromosome 22q12 abnormalities

• NF2 gene encodes for merlin protein

CLINICAL ISSUES

• Usually presents between 2nd and 4th decades with

hearing loss, ± vertigo

• Incidence: 1:25,000-30,000

• Life span substantially shortened by presence of

meningiomas and by complications related to lower cranial

neuropathies (i.e., aspiration)

DIAGNOSTIC CHECKLIST

• Carefully evaluate other cranial nerves in any new diagnosis

of schwannoma or meningioma in child/adolescent/young

adult

(Left) Axial graphic shows

bilateral cerebellopontine

angle schwannomas

pathognomonic of

neurofibromatosis type 2

(NF2). The tumor ﬊ on the

right is large, and several

small schwannomas ﬈ are

seen on the left

vestibulocochlear nerves.

(Right) Axial T1 C+ MR in a

patient with typical NF2

shows bilateral vestibular

schwannomas ſt and a right

cavernous sinus meningioma

﬇.

(Left) Axial T2WI in a 14-yearold boy with left sensorineural

hearing loss shows a mass in

the left internal auditory canal

﬇ and another lesion in the

right cavernous sinus ﬊. Note

the small nodules ſt along

the right vestibular nerve.

(Right) T1 C+ FS in the same

patient shows the left internal

auditory canal mass enhances

﬇, as does the right

cavernous sinus lesion ﬊. In

addition, 2 enhancing nodules

are seen along the cisternal

left trigeminal nerve st. The

patient was subsequently

diagnosed with NF2.

Brain: Pathology-Based Diagnoses: Malformations,

Trauma, and Stroke

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