Neurofibromatosis

From Paeds.co.uk the online paediatrician's encyclopaedia

Jump to: navigation, search

Also known as von Recklinghausen's Disease, Neurofibromatosis is a neurocutaneous syndrome which is inherited in an autosomal dominant fashion.

  • Type 1 Neurofibromatosis, NF1: "Peripheral"
  • Type 2 Neurofibromatosis, NF2: "Central"
  • There are much rarer types, eg. NF3 and 4.


Contents

Incidence

  • Incidence = 1 in 3000 live births
    • NF1: 90% (1 in 2500)
    • NF2: 10% (1 in 35 000)

Sex incidence is equal All racial groups appear to be affected equally.


Aetiology

Autosomal dominant inheritance.

  • 50% new mutation rate

NF1 - chromosome 17q11.2 - Protein: neurofibromin, though to be a tumour suppressor NF2 - chromosome 22q12.2 - Protein: neurofibromin-2.


Clinical features

NF 1 - peripheral

NF1 diagnosis requires two of the following:

  • CafĂ© au lait patches - 6 or more: (see also differential diagnoses)
    • Pre-pubertal: >5mm
    • Post-pubertal: >15mm
  • Axillary freckling (or in the groin)
  • Lisch nodules - 2 or more (hyperpigmented iris hamartomas, seen on slit lamp examination)
  • Skeletal dysplasia
  • 1 Neurofibromas or plexiform neurofibroma. (Skin tags also associated) Often increasing numbers throughout life
  • Affected 1st degree relative

Associated Endocrine disorders

  • Phaeochromocytoma
  • Acromegaly
  • Addison's disease


NF 2 - central

NF2 diagnosis requires 1 major or 2 minor criteria:

  • Major criteria:
    • Unilateral acoustic neuroma + 1st degree relative with NF2
    • Bilateral acoustic neuromas
  • Minor criteria:
    • Meningiomaa
    • Schwannoma
    • Ependymoma
    • Glioma
    • cataract

Numerous central neural tumours may occur

  • Acoustic neuroma, often bilateral (CN VIII sheath neurofibroma)
  • Meningioma
  • Spinal cord neurofibroma
    • other nerve root neurofibromas
  • Glioma
    • eg. optic glioma
  • plexiform neuroma
  • cutaneous neurofibroma (few)


Other abnormalities

Benign tumours may occasionally undergo sarcomatous change

  • Astrocytomas, medulloblastomas, ependymomas, meningiomas
  • Phaeochromocytoma, Wilms tumour, neuroblastoma
  • Ganglioneuroma
  • Renal artery stenosis
  • Fibrous dysplasia of bone
  • Obstructive cardiomyopathy
  • Pulmonary fibrosis
  • Single limb gigantism
  • Orbital haemangioma
  • Medullary thyroid carcinoma
  • learning disability


Management

Management is symptomatic.

Surgical:

  • Excision of tumours causing morbidity through local compression, where possible
    • Eg, acoustic neuroma, spinal cord lesions.
  • Cosmetic excision of lesions

Also:

  1. Assess recurrence risk in family members
  2. Cognitive assessment
  3. Ophthalmological assessment re. optic gliomas
  4. Renal artery stenosis investigation


Follow-up

  • Annual assessment for patient and famly


Prognosis, morbidity and mortality

Dependent on site and extent of lesions and their impact on surrounding structures.


References


Support Groups

Personal tools
Recommend