NF1 / Von Recklinghausen 

- most frequent of these disorders 

- 1/3000 - 1/4000. 



- VIII nerve schwannomas

- nil musculoskeletal manifestations





- 50% due to new mutation


Gene protein neurofibromin




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





- raised over the skin

- bluish in colour

- increase in number ofter puberty and with pregnancy

- nil malignant potential

- develop from small cutaneous nerves



- 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




Dermatological manifestation

- large soft tissue masses

- rough, raised vilous skin


Verrucous Hyperplasia

- skin overgrowth

- velvety, soft papillary





- 30 - 50 years

- large deep lesion

- increasing in size

- apin


Neurofibrosarcoma NF Leg MRI Coronal T2Neurofibrosarcoma NF Leg MRI Axial T1


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