Craniopharyngiomas

Craniopharyngiomas are relatively rare tumors located near or in the pituitary gland of the brain. They are among the growths known as skull base tumors. At Columbia’s Skull Base Tumor Center, our neurosurgeons specialize in providing care for patients with craniopharyngiomas. These tumors can be treated surgically, with craniotomy or endoscopic craniopharyngioma surgery. In addition, the treatment plan may include shunt placement, radiation therapy, and/or medication.

The pituitary is a small gland behind the eyes on the underside of the brain. It secretes several hormones. Near the pituitary is the hypothalamus, which also produces hormones. The gap between the pituitary and hypothalamus is bridged by the pituitary stalk. The pituitary stalk is where craniopharyngiomas begin growing; later, they tend to expand into the neighboring pituitary and hypothalamus.

A craniopharyngioma is a type of skull base tumor—a growth on the base of the skull. Craniopharyngiomas typically grow slowly and are benign. Even so, they can cause harm by pressing on and interfering with the functions of adjoining structures. As a craniopharyngioma grows, it may exert pressure on the pituitary, the hypothalamus or the optic nerve. By the time the tumor produces symptoms, it is often quite large. Craniopharyngiomas can grow back after initial treatment and then must be treated again.

Despite these challenges, patients with craniopharyngiomas have a good chance of recovery.

Symptoms

Most patients have vision problems, such as vision loss and diplopia, caused by the tumor pressing on the optic nerve.

As craniopharyngiomas grow larger, they can increase intracranial pressure. This can produce a variety of symptoms: headache, nausea, vomiting, and poor balance, for example. Large tumors can also block the flow of fluid in the brain, which leads to hydrocephalus and a further increase of pressure on the brain.

Craniopharyngiomas also often disrupt hormone production by the hypothalamus and pituitary gland. Common symptoms of such disruption include increased thirst and urination, slowed growth, weight gain, and/or low energy.

Diagnosis

To fully identify symptoms, a neurological examination is performed. This exam consists of evaluating sense of smell, hearing, swallowing, eye movements, sensation, motor function, balance, and coordination. An eye examination is also usually needed to identify any problems with vision. To detect altered hormone levels, a blood test is performed.

Imaging tests—magnetic resonance imaging (MRI) and/or computed tomography (CT) scans—can reveal the size and precise location of the craniopharyngioma. A contrast enhancement is often used with either test to increase the clarity of the image. CT scan is particularly suited for visualizing this type of tumor because it can show tumors containing a buildup of calcium especially well, and most craniopharyngiomas have a buildup of calcium.

A biopsy is typically performed before or during surgery if the imaging tests do not confirm that the tumor is a craniopharyngioma.

Risk Factors

As for most brain tumors, the cause of craniopharyngiomas is currently unknown.

Craniopharyngiomas occur in children more often than adults. In children, craniopharyngiomas make up about 6 percent of brain tumors. They most often occur in children ages 5 to 14. In adults, these tumors are particularly rare, but when they do occur, individuals are usually over the age of 65.

Treatments

At Columbia, our neurosurgeons and multidisciplinary team of specialists use the most sophisticated techniques to treat craniopharyngiomas, providing patients with optimal results.

Craniopharyngioma surgery to excise the tumor is typically the first treatment step. Technological advances have made craniopharyngiomas much easier to treat with surgery, and our neurosurgeons can remove a craniopharyngioma in one of two ways. Both surgical techniques are effective; our neurosurgeons are experts in choosing the technique best suited for a particular patient and tumor.

The traditional approach is open surgery, in which a neurosurgeon performs a craniotomy to gain access to the brain and then navigates around brain tissue to reach the tumor.

A newer technique is endoscopic trans-nasal surgery, in which a neurosurgeon goes through the natural openings of the nose to access the tumor. Through these natural openings, the neurosurgeon performs the entire surgery with the help of small, advanced surgical tools, such as an endoscope.

During surgery, physicians resect as much of the tumor as is safely possible. Complete resection is not always advisable because craniopharyngiomas tend to grow on or near the hypothalamus, pituitary stalk, the optic nerve, and other structures important to healthy body function. Subtotal resection may be the preferred course if complete resection would risk harming critical neural structures.

Residual tumor can be treated using radiation therapy. In fact, some patients may be treated with radiation therapy alone, not surgery. (Children do not undergo radiation therapy when they are younger than age 3 because radiation therapy can interfere with early brain development.)

If hydrocephalus is present, a neurosurgeon may place a shunt during surgery to relieve the pressure and allow fluid to flow normally.

If hormone levels are too high or low, medications can relieve symptoms and restore normal levels. An endocrinologist will monitor a patient’s hormone levels and overall health over the long term.