Neurofibromas are benign (non-cancerous) tumours that develop on nerves, usually in the peripheral nervous system. They are usually associated with neurofibromatosis type 1 (NF1), a genetic disorder that causes multiple neurofibromas to form throughout the body. These tumours are composed of a mixture of cells, including nerve cells, Schwann cells (which form the myelin sheath around nerves), and fibroblasts (cells that form connective tissue).
Key characteristics of neurofibromas include:
Size and Growth: They vary greatly in size, from small, inconspicuous tumours to large, growing masses. Most grow slowly over time.
Symptoms: Often, they don’t cause pain or symptoms until they press against surrounding tissue or nerves. However, some may experience discomfort, pain, numbness, or weakness depending on their location.
Appearance: Neurofibromas can appear as soft, flesh-coloured lumps on the skin or as deep, firm lumps under the skin.
Types of Neurofibromas:
Cutaneous neurofibromas: These are the most common type and appear on the surface of the skin.
Subcutaneous neurofibromas: These are located deep under the skin and can cause more significant problems.
Plexiform neurofibromas: These are larger, more diffuse, and can grow along the neural pathways. They are associated with more complex symptoms, including disabilities and functional impairments.
Causes:
Genetic Mutation: Neurofibromas usually result from mutations in the NF1 gene, which causes the production of a protein called neurofibromin. This protein helps regulate cell growth. A mutation leads to uncontrolled cell growth and the development of neurofibromas.
Inheritance: NF1 is inherited in an autosomal dominant pattern, meaning that a person with one copy of the mutated gene has a 50% chance of passing it on to their children.
Treatment:
Monitoring: In many cases, if neurofibromas do not cause significant symptoms, doctors will monitor them over time.
Surgical Removal: If lumps cause pain, functional problems, or cosmetic concerns, they may be surgically removed. However, they can sometimes recur after removal.
Medication: Although there are no specific medications for neurofibromas, pain management and treatment for NF1 complications are options.
Complications:
Although neurofibromas are benign, in rare cases, they can become malignant and develop into malignant peripheral nerve sheath tumours (MPNSTs). This change is more common in people with NF1.
If you suspect or are concerned about neurofibromas, it is best to consult a healthcare provider for a proper diagnosis and management plan.