Neurofibroma – Symptoms and Causes
Overview
Neurofibromas are soft tumors that develop on or underneath the skin from peripheral nerves. These growths form within the nerve sheath, which is the protective covering around nerves. They can appear anywhere in the body where nerves exist.
Neurofibromas are typically benign (non-cancerous). The risk of a neurofibroma becoming cancerous is very low, though this transformation can occur in rare cases.
Symptoms
Neurofibromas may not always cause symptoms. When symptoms do appear, they tend to be mild.
Common signs of neurofibromas on or under the skin include:
- A bump on the skin (typically skin-colored, pink, or tan)
- Pain
- Bleeding
When neurofibromas grow large or press against nerves, they may cause:
- Pain
- Tingling sensations
- Numbness or weakness
- Facial appearance changes (if located on the face)
People with neurofibromatosis type 1 (NF1) often develop multiple neurofibromas that increase in number as they age. These individuals may develop plexiform neurofibromas, which affect multiple nerves simultaneously. These larger tumors can:
- Grow to significant size
- Cause considerable pain
- Potentially become cancerous
If you notice unusual bumps or experience unexplained pain, tingling, or weakness, consult with a healthcare provider for proper evaluation.
Causes
Neurofibromas can develop without any clear reason. They may also appear in people who have the genetic disorder neurofibromatosis type 1. These nerve tumors typically affect adults between 20 and 30 years of age.
These tumors commonly develop in the center of a nerve. Sometimes they affect multiple nerve bundles simultaneously, creating what doctors call a plexiform neurofibroma, which is typically seen in people with NF1.
Risk Factors
The main known risk factor for developing neurofibromas is having neurofibromatosis type 1 (NF1). This genetic condition causes people to develop multiple neurofibromas throughout their body, along with other symptoms.
NF1 can be inherited. About half of people with NF1 received the gene from a parent. The other half develop NF1 through new genetic changes.
Most people who have neurofibromas do not have NF1. These individuals may develop a single neurofibroma without having the genetic condition.
There are no other clearly established risk factors for developing neurofibromas. Research continues to investigate potential environmental factors or other genetic conditions that might increase risk.
