Introduction:
A rare variety of benign brain tumors that originate near the pituitary gland is known as craniopharyngioma. The pituitary gland is a small endocrine gland known as the ‘master endocrine gland.’ Craniopharyngiomas are slow-growing tumors, and as they grow, they may impact the pituitary gland and other surrounding brain structures. They can affect the functioning of the pituitary gland and other structures. There are two types of craniopharyngiomas. Moreover, the exact cause of the occurrence of these tumors is unknown.
What Are Craniopharyngiomas?
Craniopharyngiomas are a rare type of brain tumor derived from the pituitary gland. They can develop as solid tumors or fluid-filled sacs (cysts). Craniopharyngiomas occur primarily in children, but they may also affect adults. It may occur at any age in children, even in the neonatal and prenatal phases. However, the most common age of onset is between five and fourteen years of age in children and between 50 and 74 years of age in adults.
Craniopharyngiomas are slow-growing and do not spread to other parts of the brain. However, they may grow and press on the surrounding regions, including the pituitary gland, hypothalamus, optic chiasm, optic nerve, and fluid-filled sacs. This pressure on the surrounding parts may cause growth, vision, and hormonal problems. Approximately 10 to 15 percent of pituitary tumors are craniopharyngiomas.
What Are the Types of Craniopharyngiomas?
There are two types of craniopharyngiomas:
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Adamantinomatous Craniopharyngiomas: This type mainly occurs in children and develops from the craniopharyngeal duct. They can be solid or form a cyst and are frequently calcified.
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Papillary Craniopharyngiomas: This type arises from the anterior part of the pituitary gland. Papillary craniopharyngiomas are less prevalent as compared to adamantinomatous. They are well-circumscribed and can be solid or cystic (they rarely calcify).
What Are the Causes of Craniopharyngiomas?
Craniopharyngiomas are caused by malformation of the embryonic tissues in the sellar and parasellar regions. Both types occur from different origins.
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The exact cause of adamantinomatous craniopharyngioma is unknown, although mutations in specific genes are present in almost 70 percent of the tumors.
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Papillary craniopharyngioma occurs due to a change in the cell type of the anterior pituitary cells. This leads to the formation of nests of squamous cells. However, the exact cause of papillary craniopharyngioma is also unknown.
What Are the Symptoms of Craniopharyngioma?
Craniopharyngiomas are rare tumors with atypical and non-specific symptoms. Although these are benign tumors, they can cause symptoms due to the pressure they exert on the surrounding structures. For example, it compresses the pituitary gland and hypothalamus and crosses the optic nerves.
The signs and symptoms of this tumor are:
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Headache due to obstructive hydrocephalus.
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Hypersomnia or excessive sleep.
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Feeling unusually thirsty.
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Excessive urination.
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Vision loss is due to bitemporal hemianopia.
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Nausea and vomiting.
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Balance problems.
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Paranoid confusion, mood swings, and behavior changes.
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Slow growth in children.
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Seizures (an uncontrolled electrical activity between the brain cells).
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Growth hormone insufficiency may occur post-treatment, which may cause stunted growth and delayed puberty.
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Pituitary insufficiency may cause a reduction in prolactin production.
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Diabetes insipidus may occur due to the absence of posterior pituitary hormone.
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Adrenal insufficiency leads to fatigue and low blood pressure.
Who Is More Affected by Craniopharyngioma?
Craniopharyngioma occurs equally in both men and women. It occurs mainly in children and young adults but can also affect adults. But generally, it has a bimodal incidence peak. It is prevalent in children between zero and 14 years of age and in adults between 50 to 74 years of age. Craniopharyngiomas occur in 0.5 to two percent per million each year.
How Is Craniopharyngioma Diagnosed?
The diagnosis of craniopharyngioma is based on three factors:
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Medical and clinical history.
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Physical examination.
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Laboratory testing and diagnostic imaging.
Multiple clinical symptoms suggest a diagnosis of a craniopharyngioma; for example, a patient with vision loss, headache, polydipsia, polyuria, and delayed growth should be further tested for craniopharyngiomas.
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Laboratory Tests: Blood and urine tests are used to evaluate serum electrolytes, hormones that may be affected by pituitary dysfunction, cortisol, free thyroxine, testosterone, estrogen, and prolactin.
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Diagnostic Imaging Tests: Computed tomography (CT scan) and magnetic resonance imaging (MRI) are done to detect the extent and size of the tumor. These imaging tests also evaluate the calcification and fluid accumulation inside cystic tumors. These imaging tests will also show a detailed image of the brain and the pituitary gland, which will help distinguish craniopharyngioma from other brain tumors.
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Radiology of Craniopharyngiomas: The tumor appears as a cystic mass with more than 90 percent solid component, which contains more than 80 percent calcifications and appears attenuating.
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Brain Biopsy: A biopsy may be recommended by the doctor to check for malignancy in the brain tumor. And if a doctor recommends a brain biopsy, the tumor may be diagnosed and removed simultaneously.
How Is Craniopharyngioma Treated?
The treatment of craniopharyngioma is generally the collective outcome of a skilled radiologist and neurologist.
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Neurological treatment is central to the treatment of craniopharyngioma. The tumor is surgically removed (partially or completely) after ruling out all the risks of damage to the surrounding structures. The tumor may not be removed if the surrounding structures are nearby. Radiation therapy is followed.
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Apart from neurological treatment and radiation therapy, endocrine therapy is also required to manage craniopharyngioma. This treatment is essential for patients with pituitary gland and hypothalamus dysfunction. In addition, drugs such as Octreotide may be used to reduce insulin secretion. Finally, bariatric surgery (weight loss surgery) is done in obese patients.
Surgery
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Craniotomy: The skull is opened to access the tumor. However, craniotomy also has some long-term side effects, such as problems with balancing and coordination, changes in behavior, walking difficulties, trouble with pronunciation and speech, and changes in appearance due to scarring.
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Transsphenoidal Procedure: A surgical tool is inserted through the nasal passage to access the tumor. This procedure reduces the effects on the brain.
What Is the Prognosis of Craniopharyngioma?
The prognosis and death timeline of craniopharyngioma brain tumor is usually 10 years in almost 90 percent of the patients. However, the prognosis of this condition can be affected by the following:
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Type of brain tumor.
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How quickly the tumor is growing.
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Overall health and well-being of a person.
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Location of a brain tumor in the brain.
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Weather brain tumors be removed with surgery.
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DNA (deoxyribonucleic acid) is present in brain tumor cells or not.
What Is Orbitozygomatic Craniotomy?
Orbitozygomatic craniotomy is the conventional surgical approach to treating craniopharyngiomas and other complex tumors and aneurysms of the brain. It is based on the principle that it is safer to remove extra bone than brain manipulation. To remove craniopharyngioma using this technique, make an incision in the scalp and remove the bone that forms the contour of the orbit and cheek. Removal of the bone allows surgeons to get easy access to the areas of the brain that are difficult to reach. After the procedure is completed, the surgeon places the bone segment back in its original position. This surgery is often followed by hormone replacement therapy.
Conclusion:
Craniopharyngioma is a benign tumor originating from the pituitary gland and hypothalamus. They show signs and symptoms due to pressure exerted on the surrounding structures, causing growth, vision, and balance problems. Treatment includes surgical removal, followed by radiation therapy. Craniopharyngiomas are rare tumors and can be diagnosed several years after the appearance of symptoms. An early diagnosis is beneficial and can prevent long-term complications.