Craniopharyngioma
Everything about the causes, symptoms, and most common treatments for the benign cyst located near the pituitary gland at the base of the brain.
Symptoms and Causes
Craniopharyngioma is a non-cancerous brain tumor that usually develops near the pituitary gland. This gland produces hormones that regulate numerous bodily functions, including milk production, thyroid function, fertility, immune system activity, and metabolism.
It is classified into two types based on histology, that is, its microscopic structure:
- Adamantinomatous craniopharyngioma: composed of nests of epithelial cells arranged in a palisading pattern. It contains keratin nodules with a high tendency to calcify. In most cases, it has cysts filled with viscous brown fluid containing cholesterol crystals.
- Papillary craniopharyngioma: a solid tumor (not cystic) formed by finger-like projections called papillae. It is less common than the adamantinomatous type.
Craniopharyngioma is very rare, with an estimated incidence of 1–3 cases per 100,000 individuals. The prognosis is generally favorable, with complete cure rates ranging from 80–90%.
Symptoms
The most frequent symptoms of craniopharyngioma include:
- Hydrocephalus: accumulation of cerebrospinal fluid in the brain if the cyst is located in the third ventricle, leading to increased intracranial pressure. Manifestations include:
- Headache
- Nausea
- Vomiting
- Visual changes
- Progressive vision loss
- Diabetes insipidus: if the tumor damages the hypothalamus, antidiuretic hormone production is altered, causing:
- Increased urination
- Intense thirst
- Growth retardation
- Weight gain
- Fatigue
- Sleepiness
- Cold intolerance
- Galactorrhea: abnormal milk production in both men and women due to abnormal prolactin secretion
- Loss of balance
- Confusion
- Cardiac arrhythmias
- Difficulty thinking
- Gait disturbances
- Personality or behavioral changes
Causes
Although the causes of craniopharyngioma are unclear, experts believe they originate during early embryonic development and are related to abnormal cellular changes. Studies suggest different etiologies for each craniopharyngioma type:
- Adamantinomatous craniopharyngioma: often associated with activating mutations in the CTNNB1 gene, which encodes the beta-catenin protein. Beta-catenin plays a key role in cell adhesion and genetic transcription during embryonic development.
- Papillary craniopharyngioma: considered an embryonic remnant. It forms when the Rathke’s pouch fails to close properly during pituitary development.
Risk Factors
No specific risk factors for craniopharyngioma have been identified. Age, however, is relevant:
- Adamantinomatous craniopharyngioma: most frequent; incidence is higher in children aged 5–10 years
- Papillary craniopharyngioma: very rare; primarily affects individuals over 50 years old
Complications
Complications are usually related more to surgical treatment than to the tumor itself. Key complications include:
- Persistent visual impairment despite treatment
- Long-term neurological problems, such as seizures or balance disorders
- Slowed thinking
- Poor concentration
- Learning difficulties
Prevention
Craniopharyngioma cannot be prevented.
Which Specialist Treats Craniopharyngioma?
Craniopharyngioma is a condition diagnosed and treated by neurosurgery and neurology specialists. Treatment may also involve radiation oncology and medical oncology.
Diagnosis
Craniopharyngioma is diagnosed using the following procedures:
- Medical history and anamnesis: collects all relevant information about the patient’s medical background, lifestyle, general health, and reported symptoms
- Neurological examination: assesses potential abnormalities in vision, hearing, coordination, balance, reflexes, and growth. Besides indicating a high probability of a brain tumor, it helps determine its location
- Blood tests: evaluate hormone levels to detect pituitary dysfunction
- Imaging studies: magnetic resonance imaging (MRI) (radio waves and magnetic field) or computed tomography (CT) (X-rays from multiple angles) to visualize the brain, identify the cyst, and determine its location
Treatment
The primary goal of craniopharyngioma treatment is surgical tumor removal. Surgical approaches include:
- Craniotomy: open surgery involving removal of a portion of the skull to access the tumor. Once removed, the bone is replaced and fixed with plates and screws
- Transsphenoidal surgery: minimally invasive procedure accessing the cyst through the nose using an endoscope. This approach is safer and leaves no visible scars but depends on tumor size and location
When complete tumor removal is not possible to avoid damaging surrounding brain structures, additional treatments aim to control cell growth:
- Radiotherapy: high-energy radiation destroys tumor cells
- External beam radiotherapy: directs energy beams at the tumor; multiple sessions of 15–30 minutes are usually required
- Stereotactic radiosurgery: despite its name, it is non-surgical; delivers multiple precisely targeted radiation beams to the tumor
- Brachytherapy: internal radiation placing radioactive material directly in the tumor during surgery, minimizing damage to healthy tissue and maximizing radiation to the cyst
- Chemotherapy: chemical agents destroy tumor cells; delivered directly into the cyst to limit effects on healthy tissue
- Targeted therapy: drugs specifically attack chemicals within the tumor to halt growth
If hydrocephalus develops, a catheter is placed in the brain to drain fluid. The tube is inserted through a small incision in the affected ventricle, and excess fluid is usually diverted to the abdomen for natural reabsorption. Once fluid drainage is complete, the catheter is removed in a subsequent surgery.
