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Craniopharyngiomas are slow-growing or benign tumours that occur in the central part of the brain above the pituitary gland, near the hypothalamus, optic nerve and third ventricle. They occur in adults and children. They can be present at birth (called congenital), but symptoms often don’t appear until the tumour starts to grow and affect other areas of the brain.
These tumours can affect vision and hormone release from the pituitary gland and hypothalamus. Vision is often tested before treatment.
Recurrent craniopharyngiomas are tumours that have come back after treatment.
Treatment of craniopharyngiomas
Treatment of craniopharyngiomas depends on:
- the child’s age and general health
- the size and location of the tumour
- whether the tumour extends to or involves nearby important structures such as the pituitary gland, hypothalamus and optic nerve
Treatment often begins with seeing an endocrinologist. An endocrinologist is a doctor who specializes in treating hormone problems. The endocrinologist will assess any damage to the pituitary gland and can give synthetic hormones to replace any missing hormones caused by pituitary gland damage.
Craniopharyngiomas can also cause a buildup of cerebrospinal fluid (CSF) in the brain (called hydrocephalus). Depending on the symptoms, hydrocephalus may need to be treated before surgery.
Surgery is commonly used to treat craniopharyngiomas. How surgery is done will depend if the tumour is mostly solid or mostly fluid-filled (cystic). Depending on the size of the tumour, transsphenoidal surgery may be done or a craniotomy may be used to remove the tumour.
For solid tumours, the goal is to remove as much of the tumour as possible without affecting brain functions. This can be difficult because the tumour is usually close to or attached to vital structures, such as the pituitary gland, hypothalamus and optic nerve. Trying to remove a tumour from these structures would cause more harm than good. Therefore, part of the tumour is usually removed (partial resection) and radiation therapy is given to the area.
For cystic tumours, if one of the cysts is pressing against an important part of the brain and causing increased pressure, the cyst may be drained. This involves making a small hole in the skull and inserting a tube into the cyst to drain it or putting in a shunt called an Ommaya reservoir. Chemotherapy can then be injected directly into the cyst to dry out the cyst and prevent any further fluid from forming. This also makes the cyst smaller. Bleomycin (Blenoxane) is commonly used. Sometimes a radioactive substance called yttrium-90 is placed in the cyst to shrink it.
Surgery may also be used to relieve a buildup of CSF.
Radiation therapy is often given after part of the tumour has been removed to try to control the tumour. This approach is being tried because a partial resection does not stop the tumour from coming back, and a total resection is often too risky or may cause too many side effects. Even if the surgeon can completely remove the tumour, radiation therapy may be given to destroy any cancer cells that may have been left behind.
In craniopharyngiomas with many cysts, radiation may be delivered directly to the tumour by inserting radioactive material, such as yttrium-90 or phosphorous-32 into the cysts. This is called intracystic radiation therapy. The tumour receives most of the radiation, and the surrounding tissue is usually spared.
In children under 3 years old, radiation can damage developing brain cells. In these cases, doctors will try to delay giving radiation until the child is older.
Chemotherapy is not usually used to treat craniopharyngiomas. However, in craniopharyngiomas with many cysts, chemotherapy drugs (such as bleomycin) may be inserted directly into the tumour cysts. Clinical trials continue to search for chemotherapy drugs that are effective against this type of cancer.
Treatment for recurrent craniopharyngiomas
Treatment for a recurrent craniopharyngioma will depend on what type of tumour comes back (solid or cystic). Surgery or radiation or both may be used to treat a solid tumour. Intracystic chemotherapy or radiation therapy may be used to treat cysts that come back. Targeted therapy may also be used to treat recurrent craniopharyngiomas that are mostly cystic.
Many children with craniopharyngiomas are treated in a clinical trial. Clinical trials look at new ways to prevent, find and treat cancer.Find out more about clinical trials.
I’m extremely grateful to the Canadian Cancer Society for funding my research with an Innovation Grant.
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