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| Year : 2003 | Volume
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| Issue : 1 | Page : 99-101 |
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| Neurofibromatosis 2 - a case report |
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NA Pendse, V Menghani
Vardhman MRI Centre, Santokba Durlabhji Memorial Hospital, Bhawani Singh Mart, Jaipur, India
Click here for correspondence address and email
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Keywords: Neurofibromatosis, Schwannoma
How to cite this article:
Pendse N A, Menghani V. Neurofibromatosis 2 - a case report. Indian J Radiol Imaging 2003;13:99-101 |
 Introduction | |  |
Neurofibromatosis type 2 ( NF 2 ), formerly called bilateral Acoustic Neurofibromatosis, is a distinct disease which must be separated clinically and radiologically from Neurofibromatosis type 1.
According to the National Institute of Health ( NIH ) a patient is considered to have NF 2 if he/she has :
1. Bilateral Acoustic Schwannomas
2. A combination of any 2 or more of the following - Schwannoma, Neurofibroma, Meningioma, Glioma or juvenile subcapsular lens opacity with a first degree relative suffering from NF 2.
This case is being reported to highlight the latter criteria for diagnosing NF 2.
| Case report | | |
A 36 year old female presented with a 6 month history of off and on headache followed by right sided sensorineural deafness and mild gait ataxia since 1 month. There was no history of fever, earache or ear discharge, visual disturbance or trauma.
A plain and contrast enhanced MR of the Brain was performed on a 0.5 T superconducting magnet ( GE Contour i ) and revealed the following :
· A well defined, homogenous, solid, intensely enhancing right cerebellopontine angle mass involving the eighth nerve with intracanalicular extension [Figure - 1]
· Multiple, discrete, well defined, round to oval, solid, intensely and homogenously enhancing extra axial masses attached to the falx cerebri [Figure - 2][Figure - 3]. In addition, similar masses were seen in the left Parietal convexity, left Tentorial leaf, right medial Temporal region and at the sinus confluence [Figure - 4]
· Enlargement and abnormal enhancement of the Choroid plexus in the left Temporal horn [Figure - 5]
These indicated respectively an 8th nerve Schwannoma, multiple Meningiomas and an enlarged Choroid plexus.
| Discussion | | |
Neurofibromatosis type 2 is also known as Central Neurofibromatosis or Bilateral Acoustic Schwannomas (BAN).
It is an Autosomal Dominant disease related to deletion defects from chromosome 22 [1],[2].The reported incidence is 1 : 50,000.
The NIH Consensus Committee has defined clinical criteria for NF 2. Bilateral Acoustic Schwannomas are diagnostic.
A patient is also considered to have NF 2 if there is a first degree relative with NF 2 plus either an eighth nerve mass or any two or more of the following ; Schwannoma, Neurofibroma, Glioma, Meningioma or juvenile subcapsular lens opacity [1],[2],[3],[4].
Cutaneous markers are rarer in NF 2 as compared to NF1. CNS lesions are seen in virtually all cases and include neoplasms (Cranial nerves and Meninges), non neoplastic intracranial calcifications and spinal cord nerve root tumors [3].
Intracranial Schwannomas most frequently affect the 8th nerve complex and bilateral tumors are the hallmark of NF2. Unilateral tumors typically arise from the Vestibular nerve. The Trigeminal (CN V ) nerve is the next most frequently affected cranial nerve. Although isolated Schwannomas may occur spontaneously, presence of an Oculomotor, Trochlear or Abduscent nerve tumor should raise the suspicion of NF 2. Similarly, involvement of more than one nerve should warrant a work up for NF 2.
Schwannomas are well demarcated solid masses that are iso to hypointense on T1 and iso to hyperintense on T2 weighted images. Intense and homogenous enhancement is usual.
Intracranial Meningiomas found in NF 2 are usually multiple and appear as well circumscribed intensely enhancing extra axial masses with dural attachment [2],[4].
Other associated intracranial lesions are non neoplastic calcifications with involvement of the Choroid plexus being most common. Cerebellar and cerebral cortical calcifications may also be seen [3].
Spinal lesions in NF 2 include Meningiomas and Schwannomas. Multiple masses along exiting roots are common to both NF 1 and NF 2. In NF 2 they are mostly Schwannomas [5] .
Peripheral nerve Schwannomas may also be seen and axonal peripheral neuropathy due to compression is common. [6]. Intramedullary tumors are common in NF 2 and are mostly Ependymomas.
Eye findings in NF 2 are presenile opacities and cataracts without Lisch nodules [7] .
Osseous abnormalities seen in NF 2 are secondary to spinal tumors and unlike NF 1 dural dysplasia is not a feature.
| Conclusion | | |
Based on these findings the possibility of NF 2 was considered. Spinal MRI did not reveal any tumors. Detailed history taking revealed that the patient's maternal aunt was a diagnosed case of NF 2.
This fact and the presence of an 8th nerve Schwannoma,multiple Meningiomas and enlarged Choroid plexus fulfilled the diagnostic criteria for NF 2.
| References | | |
| 1. | Martuza RL, Eldridge R: Neurofibromatosis 2 ( bilateral acoustic neurofibromatosis ). N Engl J Med 318:684,1988.  |
| 2. | Aoki S, Barkovich J, Nishimura K, Kjos B, Machida T, Cogen P, Edwards M, Norman D : Neurofibromatosis type 1 and 2 : Cranial MR findings. Radiology 172: 527, 1989. |
| 3. | Osborn Anne G, Disorders of Histogenesis : Neurocutaneous Syndromes, Diagnostic Neuroradiology : Mosby- Year Book, 1994 : 84 - 93. |
| 4. | Atlas Scott W, CNS manifestations of the Phakomatoses and other inherited syndromes : MRI of the Brain and Spine, 2nd Ed : Lipincott Raven, 1996 : 781 - 786. |
| 5. | Mautner VF, Tatagiba M, Lindenau M, Funsterer C, Pulst SM, Baser ME, Kluwe L, Zanella FE : Spinal tumors in patients with neurofibromatosis type 2. AJR 166 ( 5 ) : 1231, 1996. |
| 6. | Sperfeld AD, Hein C, Schroder JM, Ludolph AC, Hanemann CO : Occurrence and characterization of peripheral nerve involvement in Neurofibromatosis type 2.Brain125 : 996, 2002. |
| 7. | Pearson- Webb MA, Kaiser - Kupfer MI, Eldridge R. Eye findings in bilateral acoustic ( central ) neurofibromatosis : association with presenile lens opacities and cataracts but absence of Lisch nodules, N Engl J Med 1986, 315 : 1553-4. |
Correspondence Address:
N A Pendse
A-12 (A), Mahaveer Udyan, Bajaj Nagar, Jaipur (Raj)-302015
India
 Source of Support: None, Conflict of Interest: None  | Check |
Figures
[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4], [Figure - 5] |
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| This article has been cited by | | 1 |
Neurofibromatosis type 2: A case report |
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| Singh, Kh.M., Kharrubon, B. | | JMS - Journal of Medical Society. 2006; 20(3): 153-155 | | [Pubmed] | |
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