Epidemiology
NF1 / Von Recklinghausen
- most frequent of these disorders
- 1/3000 - 1/4000.
NF2
- VIII nerve schwannomas
- nil musculoskeletal manifestations
Aetiology
AD
- 50% due to new mutation
Gene protein neurofibromin
Diagnosis
Young children
- multiple café-au-lait spots that appear in the first year of life.
The NIH Consensus Development Conference Statement
- diagnostic criteria for NF1 are met in an individual who has two or more of the following:
1. Six or more café-au-lait spots over 5mm in prepubertal individuals and over 15mm in postpubertal individuals
2. Two or more neurofibromas of any type or one plexiform neurofibroma
3. Freckling in the axillary or inguinal region
4. Optic glioma
5. Two or more Lisch nodules (iris hamartomas)
6. A distinctive osseous lesion such as sphenoid dysplasia or thinning of the long bone cortex with or without pseudarthrosis
7. A first degree relative (parent, sibling, or offspring) with NF1 by the above criteria.
Clinical Features
Café au lait
< 2 normal
6 or more > 0.5cm, smooth edges
Aid early suspicion of NF1
Neurofibroma
Cutaneous
- raised over the skin
- bluish in colour
- increase in number ofter puberty and with pregnancy
- nil malignant potential
- develop from small cutaneous nerves
Plexifom
- bag of worms feeling
- usually develop from major nerves
- potential to become malignant
Axilllary / Inguinal Freckling
Aids early diagnosis
- second most common feature in children
- 80%
Lisch Nodules
Hamartomas in iris
- 90% patients over 6
Optic Glioma
&0% found in NF1
- usually benign and small
- can sometimes rapidly increase in size
Elephantiasis
Dermatological manifestation
- large soft tissue masses
- rough, raised vilous skin
Verrucous Hyperplasia
- skin overgrowth
- velvety, soft papillary
Issues
Malignancy
- 30 - 50 years
- large deep lesion
- increasing in size
- apin
Congenital Tibial Pseudoarthosis
- normally 1 per 140 000
- 3% of NF1
- see article
Spinal Deformities / Kyphosis / Scoliosis
- 30% have spinal deformity
- dystrophic and non dystrophic
- recommend earlier fusion at curves > 35o
- higher incidence of pseudoarthrosis
- all require MRI prior as high incidence of intraspinal lesions
- see Paediatrics / Spine / Scoliosis / Other / Neurofibromatosis