DR Medhat MRCP

Neurofibromatosis
- Is a genetically-inherited disorder in which the nerve tissue grows tumors
(neurofibromas) that may be benign and may cause serious damage by compressing
nerves and other tissues.
• Pathogenesis :
- There are two types of neurofibromatosis, NF1 and NF2.
- Both are inherited in an autosomal dominant fashion.
- NF1 is also known as von Recklinghausen's syndrome which is caused by a gene
mutation on chromosome 17 which encodes neurofibromin and affects around 1 in
4,000.
- NF2 is caused by gene mutation on chromosome 22 and affects around 1 in 100,000
• Pathology :
- The disorder affects all neural crest cells (Schwann cells, melanocytes and
endoneurial fibroblasts). Cellular elements from these cell types proliferate
excessively throughout the body, forming tumors.
• Features :
NF1
Café-au-lait spots (= 6, 15 mm in diameter)
Axillary/groin freckles
Peripheral neurofibromas
NF2
Bilateral acoustic neuromas
Iris: Lisch nodules in > 90%
Scoliosis
Axillary freckles
Peripheral neurofibromatosis
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