Craniopharyngioma

Craniopharyngioma is a slow-growing, non-cancerous brain tumor that develops near the pituitary gland (a small endocrine gland at the base of the brain which produces several important hormones) and the hypothalamus (an endocrine organ which controls the release of hormones by the pituitary gland).^[1][2][3] This tumor most commonly affects children between 5 and 10 years of age; however, adults can sometimes be affected.^[1] Although craniopharyngiomas are not cancerous, they may grow and press on nearby parts of the brain, causing symptoms including hormonal changes, vision changes, slow growth, headaches, nausea and vomiting, loss of balance, hearing loss, and changes in mood or behavior.^[2] The cause of these tumors is not well understood; however, researchers suspect that they begin to form during the early stages of embryo development in pregnancy (embryogenesis) and may result from metaplasia (abnormal transformation of cells).^[2][4] Treatment for craniopharyngioma varies and may involve surgery to remove the tumor, radiation therapy, chemotherapy, biologic therapy, and/or hormone therapy to replace various hormones no longer produced or secreted due to the tumor or its treatment.^[2][5]

 

Craniopharyngioma may cause symptoms by increasing the pressure on the brain (intracranial pressure), disrupting the function of the pituitary gland, and/or damaging the optic nerve. Symptoms vary from person to person and depend on the specific location of the tumor and its relationship to other adjacent structures.^[1][4][6][2]

• Increased pressure on the brain may cause hydrocephalus, headache, nausea, vomiting (especially in the morning), and difficulty with balance.

• Damage to the pituitary gland may cause hormone imbalances that can lead to many signs and symptoms such as:

• deficiency of growth hormone, gonadotropin, thyroid stimulating hormone, and/or adrenocorticotropic hormone
• excessive thirst and urination (diabetes insipidus)
• sleep disturbances
• delayed puberty and stunted growth
• weight gain or obesity, fatigue, cold intolerance, constipation, decreased mental function, behavioral symptoms (hypothyroidism symptoms)
• adrenal failure symptoms (heart arrhythmias, confusion, lethargy, orthostatic hypotension, low blood sugar)
• changes in personality or mood (such as feeling depressed or having anxiety)

• Damage to the optic nerve may result in vision problems.^[1][4][6][7]

Symptoms are often permanent, and may be worse after surgery to remove the tumor.^[1] People with craniopharyngioma often have impaired psychosocial health in addition to physical health, both of which contribute to reduced quality of life.^[7]

About 80% of adults with this tumor complain of decreased sexual drive, and almost 90% of men complain of impotence, while most women have absent menses (amenorrhea).^[4]

Because craniopharyngioma typically is a slow-growing tumor, symptoms frequently develop very slowly. The time interval between the onset of symptoms and diagnosis usually ranges from 1-2 years.^[4]

The cause of these tumors is not well understood; however, researchers suspect that they begin during the early stages of development in pregnancy (embryogenesis) and may result from metaplasia (abnormal transformation of cells). Craniopharyngiomas are thought to arise from epithelial remnants of the craniopharyngeal duct or Rathke's pouch, (an outpouch of the primitive oral cavity that forms the anterior part of the pituitary gland). Embryonic cells (early fetal cells) from abnormal development of the craniopharyngeal duct or anterior pituitary gland may give rise to a craniopharyngioma. These tumors are closely related to another cystic mass occasionally seen in the pituitary called Rathkes cleft cyst.^[3][4][8]

Treatment for craniopharyngiomas has been controversial. Two main management options have primarily been used: attempt at complete removal (gross total resection), or partial removal (partial resection) followed by radiation therapy to treat residual disease.^[6] Advances in techniques used in neurosurgery have made total resection possible in more cases, but improvements in radiation therapy techniques have also made this option more effective and safe. There currently is no firm consensus of opinion regarding the best treatment option.^[6] Unfortunately, even following treatment, many people experience endocrine, vascular, neurologic, and/or visual complications. Psychological, social, and emotional problems are also common.^[6][9] Panhypopituitarism (when the pituitary gland does not make most or all hormones) and hypothalamic dysfunction are prevalent and are treated with hormone therapy to replace various pituitary and hypothalamic hormone deficiencies.^[5] Early studies suggest that oxytocin (a less understood hormone often not replaced) may benefit some people with certain symptoms of hypothalamic dysfunction such as obesity and behavioral issues; however, additional research on larger groups of people is needed to determine its role in therapy.^[9][5][10]

An experienced multidisciplinary team of specialists (neurosurgeon, radiation oncologist, neuro-oncologist, endocrinologist, ophthalmologist) is essential for the best treatment of both pediatric and adult patients with craniopharyngiomas.^[6]

The prognosis for each patient depends on several factors, including the ability of the tumor to be completely removed and the presence of neurological problems or hormonal imbalances caused by the tumor prior to treatment, as well as caused by the treatment itself. Most of the problems with hormones and vision do not improve with treatment, and sometimes the surgery can make them even worse, because it may damage the brain structures neighboring the tumor.^[1]

Craniopharyngiomas tend to develop again, mostly in the first 3 years after surgery. Overall recurrence rates range from 0-17% after total removal of the tumor and from 25-63% after partial removal of the tumor with radiotherapy.^[4] 

Several journal articles describe an association between craniopharyngioma and cataplexy (sudden loss of muscle tone) and/or narcolepsy. Most of these articles connect the symptoms to damage in the hypothalamus.^[11][12][13]

To read more about the association between craniopharyngioma and cataplexy and/or narcolepsy, visit the following link to articles from PubMed, a searchable database of medical literature.