Neurofibromata
Pathology
- Neurofibromata
- Benign tumour derived from peripheral nerve elements
- Histologically consist of Schwann cells (appears as bundle of elongated wavy spindle cells)
- Associated with collagen fibrils and myxoid material
- Often not encapsulated (cf neurilemmas - the other common benign tumour of peripheral nerves - which are always encapsulated)
- Neurofibromatosis
- Multiple neurofibromata in a patient in combination with other dermatological manifestations (6 cafe au lait spots)
- Autosomal dominant inheritance
- Type I: Von Reckinghausen's disease: Chromosone 17
- Type II: Bilateral acoustic neuromas: Chromosome 22. Variable penetrance. Cutanous signs less seen.
Approach
- Examine as for any lump
Neurofibroma
Plexiform neurofibroma
- Inspect
- May be solitary or multiple
- Pedunculated nodule
- If arising from deeper nerves can result in severe deformity due to diffuse enlargement of the peripheral nerve with involvment of the skin (plexiform neurofibroma)
- Associated cafe au lait spots
- Palpate
- Soft / fleshy in consistency
Completion
- Ask how lump affects life
- If Multiple neurofibromata
- Test cranial nerves (esp VIII - Type 2, bilateral acoustic neuromas)
- Measure the BP (associated phaeochromocytoma)
Complications of Neurofibroma
- Direct pressure effects: spinal cord / root compression
- Deafness (if VIII involved)
- Sarcomatous transformation - occurs only in Von Reckinghausen's disease in 5-13% of cases)
- Intra-abdominal effects - obstruction, chronic GI bleeds
- Skeletal changes - can cause kyphoscoliosis, cystic changes and pseudoarthrosis
Treament options
- Non-surgical
- Leave alone if asymptomatic and patient does not want intervention
- Surgical: only indicated if malignant growth suspected
- Post excision regrowth is common
- Neurofibromata cannot be surgically detached from the underlying nerve
