Craniopharyngioma, which was first identified by Zenker in 1857, is a type of brain tumor that primarily affects children. It is a slow-growing, benign tumor that has the ability to metastasize and produce symptoms very much like those of malignant cancers. These tumors grow along the pituitary stalk, and they can cause growth failures such as the delayed onset of puberty. They are sometimes called adamantinomas, Rathke pouch tumors, or hypophyseal duct tumors, and they account for up to nine percent of all brain tumors that affect children. Their causes are unknown.
Craniopharyngioma Signs and symptoms
Craniopharyngiomas develop slowly, and often do not produce noticeable symptoms until they reach around 3 cm in diameter. After symptoms manifest, diagnosis may take up to two years. The most common symptoms include severe headaches, endocrine dysfunction, and vision problems. Some patients may also experience adrenal failure (confusion, orthostatic hypotension, hyperkalemia, hypoglycemia, cardiac arrhythmias, anorexia, lethargy, nausea and vomiting), hyperthyroidism (cold intolerance, fatigue, weight gain, constipation), or excessive fluid intake and urination associated with diabetes insipidus. Children often exhibit growth failure, delayed puberty, and previously undetected vision problems. In rare cases where this cancer is diagnosed in adults, they usually report decreased sex drive and diminished sexual function in general.
The general rule is that the earlier in life craniopharyngioma is detected, the better the prognosis will be. In patients under twenty years old, a survival rate of five years after diagnosis is 99%. At ten years, the survival rate is still 90%, but after twenty years, the survival rate for pediatric craniopharyngioma drops to around 60%. In patients over sixty-five, the survival rate after five years is 38%. Even when the craniopharyngioma is cured, many patients may still experience permanent visual, hormonal, and neurological problems.
When craniopharyngioma is suspected, radiography may detect abnormalities, but CT scans, MRI tests, and magnetic resonance angiography (MRA) are necessary to determine the details of the condition and the best course of treatment. These tests are usually accompanied by formal visual field documentation and neuropsychological assessments, as well as complete endocrinologic and neuro-ophthalmologic evaluations.
Since chemotherapy is an ineffective treatment for craniopharyngioma, total surgical resection is the ideal approach. This procedure may remove the tumor, although post-surgical recurrence rates reach 20%. Patients who undergo hypothalamic surgical resection risk permanent psychosocial dysfunction that results from damage to the hypothalamus. When total surgical resection is not possible because the risk to the hypothalamus is too great, doctors may use partial surgical resection followed by radiation therapy. If craniopharyngioma does recur post surgery, it can often be controlled by injection of a drug called bleomycin, or internal irradiation with radioisotopes.