Craniopharyngioma

Craniopharyngiomas are benign tumors that occur at the base of the brain, above the pituitary gland. It is a slow-growing, extra-axial, epithelial-squamous, calcified, cystic tumor arising from remnants of the cricopharyngeal duct or Rathke cleft. The condition is more commonly seen in the age group of 5-10yr and 50-60yr. It occurs more commonly in males than females. Various theories have been suggested to explain the occurrence of this condition which include embryogenetic theory, metaplastic theory, and mixed type.

The symptoms of patients with craniopharyngioma vary from person to person depending on the location and the severity. The patient may present with visual symptoms, hormonal imbalances, short stature, delayed puberty in children decreased libido, amenorrhoea, diabetes insipidus, and behavioral change due to frontal or temporal extension

The diagnosis is confirmed based on the findings seen on the imaging tests to look for the presence of the tumor, its size, location, and spread of the tumor. A biopsy may be required to confirm the diagnosis. Treatment option involves surgical removal, radiotherapy, hormonal therapy, and chemotherapy which can be given singly or in combination. Treatment is more effective if given in the early stages.

Craniopharyngioma: Causes

The exact cause of craniopharyngioma is unknown, but several theories have been suggested to explain the development of craniopharyngioma which include −

• The embryogenetic theory suggests the development of the adenohypophysis and transformation of the remnant ectoblastic cells of the cricopharyngeal duct and the involuted Rathke pouch. Rathke pouch and the infundibulum develop during the fourth week of gestation and together from the hypophysis. Rathke cleft, together with remnants of the cricopharyngeal duct, can be the site of origin of craniopharyngiomas.

• The metaplastic theory relates to the residual squamous epithelium which may undergo metaplasia.

• The dual theory explains the craniopharyngioma spectrum. Adamantine type, most common in childhood due to embryonic remnants. Adult type is a squamous papillary that occurs due to metaplastic foci derived from mature cells of the anterior hypophysis. And there is a mixed type craniopharyngioma.

• Some craniopharyngiomas are monoclonal in origin, and cytogenetic abnormalities have been reported in chromosomes 2 and 12. Mutations of the β-catenin gene have been identified in 70% of adamantinomatous craniopharyngiomas.

Some studies have shown that developmental abnormalities, exposure to radiation Inflammatory conditions of the brain may also increase the risk of developing craniopharyngiomas.

Craniopharyngioma: Symptoms

The symptoms of Craniopharyngiomas vary from person to person depending on the size, location, and structures affected by the tumor. Some of the most common symptoms include −

• Patients with craniopharyngiomas more commonly present with visual disturbances, such as reduced or blurring of vision, double vision, and loss of peripheral vision which occurs due to the compression of the optic nerve by the tumor. In severe cases, the person can become completely blind due to the development of optic atrophy

• Headaches are worse in the morning and may be associated with vomiting or nausea.

• When the craniopharyngiomas develop near the pituitary gland the person can have hormonal imbalances which lead to symptoms, such as fatigue, weight gain or loss, growth problems, and delayed puberty.

• Changes in the mood such as irritability, anxiety, or depression, or the person may feel changes in their personality.

• Some patients may present with cognitive difficulties, such as difficulty with memory, attention, or concentration.

Other symptoms such as seizures, difficulty swallowing or speaking, and loss of coordination or balance can be present in some patients.

Craniopharyngioma: Risk Factors

There are no specific risk factors present but some of the factors can increase the risk of developing craniopharyngiomas which include −

• Tumor tends to peak in the 5to14-year-old age group and again in adults over the age of 50.

• Slightly more common in males than in females.

• Exposure to radiation, particularly during childhood

• Genetic mutations such as mutations of BRAF and CTNNB1 genes are known to increase the risk

• People with pituitary adenoma

• People with certain medical conditions, such as hypothyroidism or obesity are at risk

Craniopharyngioma: Diagnosis

Diagnosing a craniopharyngioma is based on the clinical presentation and some of the investigations which include −

• History of the symptoms and family history should be asked

• Neurological examination to assess the brain and nervous system function should be done in involve testing of reflexes, muscle strength, coordination, and sensation

• Imaging tests, such as magnetic resonance imaging (MRI) or computed tomography (CT) scans, are done to look for the presence of the tumor, its size, location, and spread to the other parts of the brain.

• Blood tests may be done to check for any hormonal imbalances that may be caused by the tumor.

• A biopsy is required to confirm the diagnosis of a craniopharyngioma. In which, a small sample of tissue from the tumor is taken and examined under a microscope.

• Ophthalmological evaluation should be done to know the involvement of the optic nerve.

Additional tests may be required to look for the extent of the tumor which includes; imaging tests, such as positron emission tomography (PET) scans, and additional hormone testing.

Craniopharyngioma: Treatment

The treatment of craniopharyngioma depends on the size, location, and spread of the tumor. The treatment includes −

• Surgery is a first-line treatment. The surgery involves the removal of the tumor as much as possible without causing damage to the surrounding brain tissue. In some cases, complete removal of the tumor may not be possible, especially if the tumor is located close to critical brain structures. In such cases, a partial removal may be done to relieve pressure on the brain and reduce symptoms.

• Radiation therapy is used as adjunctive after surgery to kill the remaining cancer cells and prevent the tumor from growing back. This may involve external beam radiation therapy or stereotactic radiosurgery. Radiation therapy may also be used as a primary treatment for craniopharyngioma in cases where surgery is not an option.

• Chemotherapy is used in cases where the tumor has spread to other parts of the brain or if radiation therapy is not effective.

• Hormone replacement therapy is required in patients where the Craniopharyngioma affects the pituitary gland and disrupts the production of hormones.

Craniopharyngioma: Prevention

There are no specific ways known to prevent the development of craniopharyngioma. However, some of the steps taken can help to reduce the risk which includes −

• Avoid exposure to high levels of ionizing radiation.

• Avoid exposure to certain chemicals

• Adequate treatment of any illness if the person is suffering from

• Healthy diet and regular exercise to improve the overall health

• Regular health checkups can help to identify the disease in the early stage and help with inadequate treatment

Conclusion

Craniopharyngioma is a tumor that is known to arise from the remnants of the cricopharyngeal duct. The tumor is located in the sellar region and depending on its presence it can be chiasmal, pre-chiasmal, and post-chiasmal presenting with various visual disturbances. Tumor located near the pituitary gland and produces hormonal disturbances. The symptoms vary depending on the locations and spread of the tumor.

The exact cause is unknown but various studies have explained its development. Imaging tests are required to look for the presence of the tumor and a biopsy may be required for confirmation. Additional tests like positron emission tomography scans can be required to look for the spread of the tumor. The treatment involves a combination of surgery, radiotherapy, chemotherapy, and hormonal replacement.