Complications of neurofibromatosis vary, even within the same family. Generally, complications result from tumors that affect nerve tissue or press on internal organs.
Complications of NF1 include:
Neurological problems. Learning and thinking difficulties are the most common neurological problems associated with NF1. Uncommon complications include epilepsy and the buildup of excess fluid in the brain.
Concerns with appearance. Visible signs of neurofibromatosis — such as extensive cafe au lait spots, many neurofibromas in the facial area or large neurofibromas — can cause anxiety and emotional distress, even if they're not medically serious.
Skeletal problems. Some children have abnormally formed bones, which can result in bowing of the legs and fractures that sometimes don't heal. NF1 can cause curvature of the spine (scoliosis) that may need bracing or surgery. NF1 is also associated with decreased bone mineral density, which increases the risk of weak bones (osteoporosis).
Vision problems. Sometimes a tumor develops on the optic nerve (optic glioma), which can affect vision.
Problems during times of hormonal change. Hormonal changes associated with puberty or pregnancy might cause an increase in neurofibromas. Most women who have NF1 have healthy pregnancies but will likely need monitoring by an obstetrician who is familiar with the disorder.
Cardiovascular problems. People who have NF1 have an increased risk of high blood pressure and may develop blood vessel abnormalities.
Breathing problems. Rarely, plexiform neurofibromas can put pressure on the airway.
Cancer. An estimated 3% to 5% of people who have NF1 develop cancerous tumors. These usually arise from neurofibromas under the skin or from plexiform neurofibromas. People who have NF1 also have a higher risk of other forms of cancer, such as breast cancer, leukemia, colorectal cancer, brain tumors and some types of soft tissue cancer. Women who have NF1 should start screening for breast cancer at an earlier age than the general population.
Benign adrenal gland tumor (pheochromocytoma). This noncancerous tumor secretes hormones that raise your blood pressure. Surgery is usually needed to remove the pheochromocytoma.
Complications of NF2 include:
Partial or total deafness
Facial nerve damage
Small benign skin tumors (skin schwannomas)
Weakness or numbness in the extremities
Multiple benign brain tumors or spinal tumors (meningiomas) requiring frequent surgeries