5 Things You Need to Know About Visual Pathway and Hypothalamic Glioma In Children

1. Bad News on the Brain

Brain tumors are one of the leading childhood cancers (after leukemia and lymphoma). Gliomas are tumors that grow in certain brain cells called astrocytes, which are primary in the function of blood and nerves in the brain. In the case of rare malignant visual pathway gliomas, the optic nerve (which sends signals from the eye to the brain) is affected. Most notably in children, gliomas are nearly always hypothalamic tumors. These tumors are found in the part of the brain known as the hypothalamus which, among its many roles, plays a part in the central nervous system.

2. A Tough Nut to Crack

In many cases, the only outward signs of a visual pathway glioma is some type of vision or neurological impairment, and the tumor may be found only by a vision screening while the child is showing no signs of the disease. It is usually difficult to ascertain between visual pathway gliomas and other types of hypothalamic and thalamic tumors. Hypothalamic gliomas can cause hyperactivity, headaches, euphoria and loss of normal growth in children. Tumors in the thalamus will usually result in loss of sensory functions.

3. A Link to Genetic Disorder

The cause of hypothalamic tumors is unknown, though it is believed genetics and environmental factors both play a role. In the case of visual pathway gliomas, there has been an established link between the disease and children who have neurofibromatosis type-1 (NF-1), a genetic disorder marked by skin discolorations (brown spots, freckles) as well as nerve tumors and developmental changes, in addition to the skin and nervous system, to muscles and bones as well. About 20 percent of children with NF-1 will develop a visual pathway glioma.

4. A Cancer Without Stages

Unlike most cancers, visual pathway and hypothalamic gliomas are not staged, as no universal staging system has been established. They are, however, graded (according to child's age and overall health, the size of the tumor and where it is located, whether the child has NF-1 and if the diagnosis is initial or if it is a recurrent tumor). These types of tumors are generally low grade (slow-growing). Treatment options, discussed below, depend on the grade of the tumor.

5. To Treat or Not to Treat, That is the Question

In many cases, unless symptoms worsen (or, if the child is asymptomatic, symptoms appear), a wait-and-see attitude is adopted. The child is monitored, but no treatment is initiated. This is referred to as untreated visual pathway and hypothalamic glioma. When treatment becomes necessary, surgery, radiation therapy and chemotherapy are all options, depending on the size and location of the tumor. Clinical trials should always be considered, especially in children with recurrent visual pathway and hypothalamic glioma.