Craniopharyngioma Health Article

Definition

Craniopharyngioma is a cancer which arises in the pituitary gland, in tissue originally found in the embryo. One of the most common childhood brain cancers, it is also sometimes called a Rathke's pouch tumor or a suprasellar cyst.

Description

Craniopharyngioma is the second most common type of childhood brain tumor, accounting for almost 10% of all brain tumors in children. This cancer has very little tendency to spread to other parts of the body. It readily invades local tissues, however, and since it occurs deep within the brain, invasion of local tissues alone can result in serious illness or even death.

The pituitary gland produces many hormones that play critical roles in the development and regulation of the body. Because this cancer arises in the pituitary gland, it often results in deficiencies of the various hormones that the pituitary gland produces. The tumor can be either solid or cystic or mixed, and most (up to 90%) of craniopharyngiomas contain calcium deposits, an indication of diseased tissue readily observable on x rays.

Demographics

The large majority of craniopharyngiomas are childhood tumors. The median age at diagnosis is eight years; peak incidence is between the ages of six and eleven. Almost 70% of all craniopharyngiomas occur before the age of 20, although a small peak occurs after the age of 50. Diagnosis before the age of two is very rare. Girls and boys and all races are affected equally.

Causes and symptoms

The cause of craniopharyngioma is not really understood, although it is believed to be primarily a congenital illness. Nests of embryonic cells exist in a part of the pituitary gland known as Rathke's pouch. In craniopharyngioma, these nests appear to contain cancerous cells which, over time, multiply and become a tumor.

The symptoms of craniopharyngioma can be divided into two categories. Some are nonspecific symptoms which occur because of increased pressure within the skull; some result from deficiencies of the hormones that the pituitary gland normally produces. Any individual patient may have various combinations of symptoms and both the number of symptoms and the severity of the symptoms typically increase over time. Nonspecific symptoms of increased intracranial pressure include:

• headache
• visual disturbances
• irritability
• personality changes
• mental disturbances

Symptoms that can result from hormone deficiencies include:

• diabetes
• growth retardation
• sexual dysfunction (in adults)

Diagnosis

Most patients seek medical attention because of headaches or visual disturbances, failure to match normal growth patterns (due to a deficiency of growth hormone), or symptoms of diabetes. If (after other causes of symptoms are ruled out) a craniopharyngioma is suspected, usually some kind of imaging technique is performed. Traditional x rays reveal an enlargement of the space at the base of the skull where the tumor is typically found, and will also show calcification of cancerous cells. Computed tomography (CT scan or CAT scan) may show calcification that does not show up on x rays and also shows whether the tumor is cystic or solid in nature. Magnetic resonance imaging (MRI) can show how much the tumor has invaded the surrounding tissues.

Often the amounts of pituitary hormones in the blood are measured as well. Measurements may be made of gonadatropins (hormones which regulate reproduction), thyrotropin (a hormone that regulates the thyroid gland), growth hormones (regulates growth), corticotropin (a hormone that regulates carbohydrate metabolism, vasopressin (a hormone that regulates water retention), or prolactin (a hormone that regulates milk production in mothers of infants).

Treatment team

As the understanding of cancer grows and new treatment approaches are developed, the complexity of cancer treatment also increases. Today, a multidisciplinary approach to cancer treatment is considered necessary for effective patient care. Since craniopharyngioma is a neuroendocrine tumor that occurs deep in the brain and mainly in children, optimal treatment requires a particularly complex and sophisticated team of health professionals. The types of people who may be involved in treating or caring for a patient with craniopharyngioma and their family typically include oncologists (pediatric), pathologists (neuropathologists), radiation oncologists, radiation technicians, psychiatrists, oncology social workers, nutritionists, home health care providers, endocrinologists, rehabilitative specialists, and neurosurgeons. The surgeon, specifically, should be a pediatric neurosurgeon, as these specialists have been shown to provide better long-term outcomes than general neurosurgeons.