5 answers about NF and plexiform neurofibromas

Neurofibromatosis (NF) is a rare genetic disorder caused by mutations to tumor suppressing genes. The most common form of NF is neurofibromatosis type 1 (NF1). One of the characteristic manifestations of NF1 are benign nerve tumors called neurofibromas.

Plexiform neurofibromas are neurofibromas that involve multiple nerves. They are larger than typical neurofibromas—in some cases, very large—and can grow into surrounding connective tissues and skin folds. Plexiform neurofibromas often affect children and are sometimes present at birth. They can continue to grow throughout a person’s life and can pose a significant risk to a person’s health.

What causes pNFs?

Plexiform neurofibromas are a possible outcome of having NF1, which is a genetic mutation that can be inherited or occur spontaneously. This genetic mutation impacts the body’s ability to make a tumor suppressor protein that regulates the life/death cycle of cells. NF1 affects different people in different ways, and the severity of symptoms can vary from person to person. An estimated 30 percent of people with NF1 have one or more pNFs. This percentage may be higher because not all pNFs cause symptoms and some may go unnoticed.

What are the signs and symptoms of pNF?

Plexiform neurofibromas are sometimes described as bulging and looking or feeling like a “bag of worms” beneath the skin. They can cause a range of symptoms, depending on where in the body they are located and the size.

What parts of the body can be impacted by pNFs?

They can develop just about anywhere in the body—the eye socket, face, limbs, back, chest, abdomen, and groin are common locations.

What are the potential complications of pNF?

These tumors can pose a serious risk to a person’s health. When they grow large in size, pNFs can put pressure on surrounding structures in the body. This can disrupt the normal functioning of the body and its organs, causing pain and disability. PNFs that are located in the face or head can cause disfigurement. While benign, in some cases neurofibromas can become malignant, and pNFs are more likely to become malignant than smaller neurofibromas.

Even without the presence of a pNF, NF1 is associated with a number of complications, including abnormalities in physical and cognitive development, and an increased risk of other types of tumors.

What is the treatment for NF1 and pNF?

There is no cure for NF1. Treatment for NF1 and pNF will depend on a number of factors including a patient’s age and overall health, and the size and location of the tumor or tumors. Surgery to remove problematic tumors is used in many cases. Chemotherapy and radiation therapy are also used in some cases.

Monitoring the disease through regular appointments with a healthcare provider is an important aspect of treatment. At these appointments, talk to your family's healthcare provider about what treatment options are available. Because the nerve tumors caused by neurofibromatosis can cause pain, pain management is also a focus of treatment for many patients, and physical therapy and orthopedic devices may help improve mobility issues that have resulted from NF1 or pNF.