Brief overview
- Symptoms: Skin nodules, pigment spots, bone changes, eye changes, abnormalities of blood vessels, hypertension, etc.
- Course and prognosis: Variable, worse prognosis if malignant tumors form, life expectancy reduced by approx. 15 years
- Causes and risk factors: mutation of the NF-1 gene is the cause
- Diagnosis: Based on standardized criteria
- Treatment: Surgical removal of the nodules, drugs that slow down tumor growth
What is neurofibromatosis?
Neurofibromatosis type 1 (NF1 or Recklinghausen’s disease for short) is a genetic disease. Physicians count it among the so-called phakomatoses. These are clinical pictures that are associated with the formation of certain, predominantly benign tumors of the skin and nervous system. In addition, Recklinghausen’s disease causes changes in the bones and in the vessels of the skin, eyes and brain.
Neurofibromatosis: What are the symptoms?
People with neurofibromatosis type 1 experience a range of symptoms and conditions that affect the skin appearance as well as nerves, bones, and blood vessels.
Skin changes
A particularly characteristic symptom of neurofibromatosis type 1 is the formation of skin nodules, which initially appear sporadically, but later become numerous. These so-called cutaneous neurofibromas develop along the nerves that run through the skin. They usually appear as broad or pedunculated skin nodules over the entire body, with the trunk being particularly frequently affected. The cutaneous neurofibromas are either located on the surface or, in other cases, are palpable in the subcutis.
Another indication of Recklinghausen’s disease are certain pigment spots on the skin, also known as café-au-lait spots. Although these pigment spots also occur in healthy individuals, they are usually larger and more numerous in neurofibromatosis type 1. Especially in the armpit area as well as in the groin they are often found in clusters. Since they resemble freckles in appearance, doctors also refer to this phenomenon in Recklinghausen’s disease as “freckling”.
The superficial skin tumors in neurofibromatosis usually do not cause any health complaints, but they often cause a great deal of stress for the affected person from a cosmetic point of view. In contrast, plexiform neurofibromas cause symptoms such as numbness and, more rarely, paralysis, if – depending on their size and location – they impair the function of the corresponding nerve.
More symptoms
- Bone changes: Bone cysts, bone fractures, adhesions or deformities of the vertebral bodies, deformities of the skull bone, spinal curvature (scoliosis).
- Eye changes: Tumors along the optic nerve and associated limited vision, small roundish, yellow-brown changes in the iris (so-called Lisch nodules), tumor on the optic nerve (optic glioma)
- Premature onset of puberty
- Tumors of the adrenal medulla (pheochromocytoma)
- Anomalies of blood vessels and hypertension
- ADHD, hyperactivity
In some cases, intelligence is decreased in neurofibromatosis.
Neurofibromatosis in children and babies
Neurofibromatosis in babies is usually first manifested by café-au-lait spots, which are usually noticeable in the first few weeks of life. Neurofibromas are very rare in babies and young children, with the exception of plexiform neurofibroma.
As a result of the changes in the nervous system, children with neurofibromatosis occasionally experience developmental delays, so that their motor and language skills develop more slowly. Attention and learning ability are also impaired in some children. Behavioral problems, limitations in social behavior, and physical clumsiness are other possible symptoms of neurofibromatosis 1 in children.
The head also sometimes grows faster in children with NF 1, which they occasionally feel as a result through headaches or vomiting.
What is the life expectancy?
Life expectancy is reduced by about 15 years in people with neurofibromatosis.
What causes neurofibromatosis?
The cause of neurofibromatosis lies in the genes. In affected individuals, the NF1 gene is mutated. This gene normally ensures the formation of a special protein (neurofibromin). This protein plays a key role in suppressing the development of certain tumors (tumor suppressor). Due to the genetic defect, the protective effect of neurofibromin is lost, so that the characteristic tumors of neurofibromatosis type 1 develop.
In about half of the cases, the parents have passed the genetic defect on to their children. In the other half, it has occurred as a result of spontaneous changes in the genetic material (known as spontaneous mutation).
How is neurofibromatosis diagnosed?
In order to identify the skin nodules as neurofibromas, the physician may take a tissue sample (biopsy) and have it examined by histopathology. Tumors that cannot be seen externally can be detected by magnetic resonance imaging (MRI).
The following criteria apply for the diagnosis “NF1”:
- There are six or more café-au-lait spots with a size of at least five millimeters in diameter (in patients before puberty), or 15 millimeters in adults.
- Two or more cutaneous neurofibromas are present, or one plexiform neurofibroma.
- During an eye examination, the physician detects two or more Lisch nodules on the iris.
- A tumor of the optic nerve (optic glioma) exists.
- Freckle-like skin pigmentation is seen in the axilla and groin area (“freckling”).
- First-degree relatives are known to have neurofibromatosis type 1.
If two or more of the above criteria are present, the diagnosis of neurofibromatosis type 1 is considered confirmed.
How is neurofibromatosis treated?
Since neurofibromatosis type 1 is a hereditary disease, no causal therapy exists to date. Therefore, Recklinghausen’s disease cannot be cured. However, it is possible to alleviate the symptoms of neurofibromatosis type 1:
It is possible to remove neurofibromas that cause discomfort or are particularly cosmetically distressing during surgery with a scalpel or laser.
A drug is also available to people with neurofibromatosis type 1. The active ingredient selumetinib has now been approved in Europe. This active ingredient prevents tumors from growing and sometimes even shrinks them.
