Neurofibromatosis Clinic

Children’s Medical Center of Dallas is committed to providing state of the art care for patients with Neurofibromatosis. The Comprehensive Neurofibromatosis Clinic at Children’s Medical Center of Dallas meets once per month and brings together a number of specialists involved in the care of patients with Neurofibromatosis. The clinic is headed by Dr. Laura Klesse, who along with Dr. Daniel Bowers, are pediatric neuro-oncologists in the Center for Cancer and Blood Disorders at Children’s Medical Center of Dallas. The comprehensive clinic also brings in specialists in pediatric neurology, neuropsychology, education and school services as well as representatives from the Texas NF Foundation. The Comprehensive NF program at Children’s Medical Center of Dallas currently treats over 300 active patients with NF as well as evaluates eighty new patients per year.

The NF clinic at Children’s Medical Center of Dallas treats patients with all three types of neurofibromatosis: Neurofibromatosis type 1, Neurofibromatosis type 2 and Schwannomatosis. Although these share the name of neurofibromatosis, they are distinct genetic disorders with different symptoms and presentations. There is no proven medical therapy to cure neurofibromatosis and clinical follow-up is critical. The NF clinic at Children’s Medical Center, along with our adult NF clinic at the Simmons Cancer Center is an affiliate clinic in the Children’s Tumor Foundation clinic network. The clinic is also bolstered by the strong NF research ongoing at the University of Texas Southwestern Medical Center.

Neurofibromatosis Type 1:

NF1 is a common condition which affects one in every 3000 individuals, world wide. It affects boys and girls of all races equally and affects over 100,000 Americans. NF1 is named for the neurofibromas, benign nodules under the skin, which are commonly found in patients. Patients with NF1 often present with multiple birth marks, called café au lait macules (coffee with milk) and freckles in the arm pits and near their groin. Patients with NF1 had an increased risk of learning issues, some cancers and scoliosis as well as other bone abnormalities. One of the major risks of NF1 is the growth of a plexiform neurofibroma, a large, invasive tumor which can lead to severe disfigurement or other problems. The majority of patients, however, have mild manifestations of NF1. Only about 20% of people with NF1 will have severe problems secondary to their NF.

NF1 Frequently Asked Questions:

No one in our family has it – how did our child get NF1?
Only about one half of patients diagnosed with NF1 have a family history. Once a person is diagnosed with NF1, they will have a 50% chance of passing it on to their children. For reasons that we still don’t understand, the signs and symptoms of NF can be very different even within the same family. Some people are mildly affected, while others are not.

How is the diagnosis of NF1 made?
NF1 is diagnosed when patients meet two of a list of criteria which includes:

Six or more café au lait macules – these are usually the one of the first signs of NF1.
Freckles in the axilla (arm pits) or near the groin.
Two or more neurofibromas which are benign tumors under the skin or one or more plexiform neurofibroma. Plexiform neurofibromas are bigger tumors which grow around a group of nerves.
A family member with NF1, such as a mother or father or a brother or sister.
An optic glioma, a benign tumor of the optic nerve (from the eye to the brain).
Bone abnormalities, including pseudoarthrosis.
Presence of two or more Lisch nodules in the iris. These can only be seen using a special light and have no effect on vision. They do not tend to appear until children are over 5 years of age.

There is also a genetic test for NF1 which is done on a blood sample. This test can identify most patients with NF1 (95%). The majority of the time, the diagnosis can be made based on the above criteria. In special situations, however, your doctor may recommend this testing.

Why is the clinic headed by cancer doctors?
Although most people with NF1 will have mild signs and symptoms, having NF1 does put patients at risk for certain types of cancer. The most common is a slow growing, benign tumor called a low grade glioma or pilocytic astrocytoma. In patients with NF1, these are most commonly found in along the nerve which runs from the eye to the brain (an optic glioma). Most often, these do not cause symptoms or need to be treated. It is for this reason that yearly ophthalmology exams are recommended. Patients with NF1 also have risks of other types of cancer, although these are small.

How often do we need to be seen?
We recommend that patients with NF1 be seen by a physician knowledgeable about NF at least yearly. Patients with more significant problems should be seen more frequently.

What tests do we need to have done?
Every year patients with NF1 should have a physical examination with height, weight and blood pressure measurements. For children less than eight, yearly examinations by an ophthalmologist are necessary. Radiology imaging, including MRI scans of the brain, may be done if new or concerning symptoms are found. Since learning issues are common, we recommend evaluation around the time children enter school.

Neurofibromatosis Type 2:

Neurofibromatosis Type 2 is a distinct form of Neurofibromatosis. It is less common than NF1, affecting 1 in 25,000 individuals. NF2 is characterized by tumor formation on the acoustic nerve, the nerve responsible for hearing and balance. Patients often present with ringing in their ears, loss of hearing or balance problems in their late teens or early twenties. In NF2, tumors can also form on other nerves, in the brain and in the spinal cord. The majority of these tumors are benign, but can cause significant symptoms. NF2, like NF1, is an inherited disorder and is passed down in families, although it can be diagnosed in patients without a family history.

NF2 Frequently Asked Questions:

How do I know if I have NF2?
In order to know if you have NF2, you should be seen by a physician familiar with NF2. The diagnosis is made by meeting clinical criteria. Patients who have vestibular schwannomas (acoustic neuromas or tumors on the acoustic nerve) on both sides of their head have NF2. The diagnosis can also be made if you have a family member with NF2 (a mother, father or sibling) and one of the following:

One vestibular schwannoma (acoustic neuroma) and you are younger than 30 years old.
You have two of the following list: a meningioma, a glioma, an ependymoma a schwannoma or juvenile cortical cataracts.

There is a genetic test for NF2 which may be order by your physician if the diagnosis is not clear. The genetic test, however, may not detect all patients with NF2.

How is NF2 treated?
Currently, the only known effective treatment for the tumor associated with NF2 is surgical removal or radiation therapy. Treatment is utilized in patients whom are symptomatic from their tumors. Research into medical therapies is underway.

Schwannomatosis:

Schwannomatosis is a genetic disorder in which patients can develop tumors called Schwannomas on nerves anywhere in the body. Although these tumors tend to be benign and slow growing, they are associated with significant pain and nerve dysfunction. Schwannomatosis affects 1 in 40,000 individuals. In contrast to Neurofibromatosis 1 and Neurofibromatosis type 2, the majority of patients with Schwannomatosis are due to sporadic mutations; only about 10% are inherited. The majority of patients are diagnosed in their thirties. One third of patients will have segmental Schwannomatosis, with tumors in one area of their bodies. Schwannomatosis has only recently been recognized as one of the neurofibromatoses and we still have quite a bit to learn.

How is Schwannomatosis diagnosed?
The diagnostic criteria for Schwannomatosis were first formulated in 2005. They are as follows:
Patients must be older than 30 and have:

Two or more non-intradermal Schwannomas.
Not have a vestibular schwannoma (acoustic schwannoma)
Not have a NF2 gene mutation.

Patients with a first degree relative with Schwannomatosis can be diagnosed with one non-vestibular Schwannoma. To date, there is no good genetic test for Schwannomatosis. The gene INI1 has been identified as mutated in some patients with Schwannomatosis, although it is probably not the only gene involved.

How is Schwannomatosis treated?
Unfortunately, there is no medical treatment for Schwannomatosis. Surgery remains the only treatment for Schwannomas. In some patients, surgical resection is not possible secondary to the location of the tumor. When this is the case, appropriate pain control is necessary.