Craniopharyngioma


What is a craniopharyngioma?

A craniopharyngioma is a type of brain tumor that always arises in a very specific location: immediately under and behind the frontal lobes of the brain. It actually begins from a remnant of tissue adjacent to the pituitary gland. The pituitary gland itself regulates many hormones and is connected to a part of the brain called the hypothalamus. In addition, the optic nerves, which connect the eyes to the brain, converge directly above the pituitary gland. So, when craniopharyngiomas grow and affect these structures, they can cause progressive visual loss, headaches, and/or hormonal imbalance. Sometimes, with very large tumors, the normal flow of cerebrospinal fluid is blocked and patients develop hydrocephalus.


What is the outcome?

Craniopharyngiomas are considered benign tumors; they are not cancerous. If the tumor can either be removed completely, or even if some is left but treated effectively with radiation, then the long-term outcome is quite good for the majority of patients. For some patients, the tumor will return despite many therapies. Craniopharyngiomas, particularly those that are large and those that arise in very young children remain a challenge to treat.


How serious is it?

Treatment often requires surgery and sometimes radiation therapy. Depending on how severe the symptoms are at the time of diagnosis, patients can make a complete recovery. However, because craniopharyngiomas can involve important structures, tumor growth or the treatment used can result in permanent problems such as lack of normal hormone control, visual loss, or the need for a shunt to treat hydrocephalus. In general, most children with craniopharyngiomas will require long-term monitoring of endocrine function (and treatment if the pituitary is not functioning properly), and regular MRI scans to check for any signs that the tumor has returned.


What are the treatment options?

When the tumor is not tightly attached to important brain structures, surgery by itself can result in a permanent longterm cure. This usually only happens in about a third of cases. In the majority of the remaining cases, the tumor can be mostly removed, leaving a small amount behind. In general, if there is doubt about whether any part of the tumor is left after surgery, then radiation is recommended to prevent ‘recurrence’ of the tumor. The type of radiation used depends upon the location of the residual tumor.

If there is a larger amount of tumor remaining after surgery, or if vital structures are close by, then conformal external beam radiotherapy is used. This method uses many smaller doses of radiation to protect the normal brain but there is some spread of the radiation beyond the actual target. Nevertheless, this technique is very safe and has excellent results. If there is a small, well-defined residual tumor remaining that is a safe distance from the optic nerves or hypothalamus, then Gamma Knife radiosurgery is an option. Radiation will usually affect the normal function of the pituitary and can affect cognitive function. For young children who have had a good surgical resection, an alternative option is observation with radiation treatment reserved for clear evidence of recurrent tumor growth.


What clinical trials are testing new treatments for craniopharyngioma?

In general, chemotherapy is not effective for craniopharyngioma. Some clinical trials are available at UCSF through national consortia, such as the Children's Oncology Group and the Pacific Pediatric Neuro-Oncology Consortium.

Click here for a list of trials for pediatric brain tumors currently offered at UCSF. Or contact the pediatric oncology nurse practitioner line at (415) 476-3831. 


What research is being done on craniopharyngioma?

Radiation is known to be effective in controlling the residual tumor tissue that may be left behind. Radiation oncologists are using more precise radiation treatment to target the tumor itself and spare important structures such as the pituitary gland and the optic nerves. There are ongoing laborartory studies that are attempting to identify the genetic changes that occur in these tumors so new therapies can be developed in the future.