Craniopharyngioma

What is a Craniopharyngioma?

A craniopharyngioma is a rare, benign (non-cancerous) brain tumour that arises near the pituitary gland and hypothalamus at the base of the brain, in the sellar and suprasellar region. It develops from embryological remnants of Rathke's pouch — the structure from which part of the pituitary gland forms during fetal development.

Although histologically benign (WHO grade 1), craniopharyngiomas are considered clinically aggressive due to their location adjacent to critical brain structures — the optic chiasm, hypothalamus, pituitary gland, and third ventricle. Their tendency to invade and adhere to these structures makes complete surgical removal challenging, and tumour recurrence after surgery is common. Craniopharyngiomas have a bimodal age distribution — peaks in childhood (5–14 years) and in older adults (50–75 years).

At One Brain and Spine, our Melbourne neurosurgeons manage craniopharyngiomas within a dedicated multidisciplinary team including neuro-oncologists, radiation oncologists, endocrinologists, neuro-ophthalmologists, and neuropsychologists.

What Causes Craniopharyngioma?

Craniopharyngiomas arise from embryological remnants and are not caused by any known environmental, dietary, or lifestyle factors. They are not hereditary. Two distinct histological subtypes exist:

• Adamantinomatous craniopharyngioma — more common in children; contains calcifications; associated with CTNNB1 (beta-catenin) mutations; tends to be more invasive and adherent to adjacent structures
• Papillary craniopharyngioma — more common in adults; rarely calcified; associated with BRAF V600E mutation; generally better circumscribed and more amenable to complete resection

Symptoms of Craniopharyngioma

Symptoms depend on tumour size and which adjacent structures are compressed:

Visual Disturbance

Compression of the optic chiasm causes visual field defects — typically bitemporal visual field loss (loss of peripheral vision on both sides). Visual acuity may also be reduced. Visual symptoms are present in the majority of patients at diagnosis.

Endocrine Dysfunction

Compression of the pituitary gland and hypothalamus impairs hormone production, causing:

• Growth hormone deficiency — growth retardation in children
• Diabetes insipidus — excessive urination and thirst from absent ADH
• Hypothyroidism, adrenal insufficiency — from loss of TSH and ACTH
• Hypogonadism — absent puberty in adolescents; infertility and loss of libido in adults

Raised Intracranial Pressure

Obstruction of the third ventricle causes hydrocephalus and raised ICP — headache, nausea, vomiting, and cognitive changes.

Hypothalamic Dysfunction

Hypothalamic involvement causes a loss of regulation of satiety (the feeling of fullness) and thirst.  This can result in obesity as you are unaware you are full, and fluid imbalance.  Loss of core temperature control, loss of short-term memory, sleep disturbance, and behavioural changes may also occur in this situation.

How is Craniopharyngioma Diagnosed?

• MRI of the brain with gadolinium contrast — demonstrates a sellar/suprasellar mass with characteristic mixed solid, cystic, and calcified components; defines relationship to the optic chiasm, hypothalamus, and pituitary
• CT scan — demonstrates calcification within the tumour (present in 90% of adamantinomatous type), which is a characteristic feature
• Formal visual field testing — mandatory; documents the extent of optic chiasm compression
• Full endocrine evaluation — pituitary hormone profile to identify pre-existing deficiencies before surgery

‍

Treatment of Craniopharyngioma

Treatment requires a carefully balanced multidisciplinary approach. The historical goal of radical complete surgical removal has been moderated by recognition that aggressive hypothalamic surgery causes severe long-term morbidity — particularly obesity and neuropsychological impairment. Modern management often favours limited surgery to achieve decompression, followed by radiotherapy.

Surgery

The primary goals of surgery are tumour decompression — relieving pressure on the optic chiasm (to preserve or restore vision), draining cystic components, and treating hydrocephalus. The surgical approach — transsphenoidal endoscopic (through the nose) or transcranial craniotomy — is determined by tumour location, extension, and surgeon experience. At One Brain and Spine, both approaches are available.‍

Radiotherapy

Fractionated radiotherapy is used postoperatively for residual or recurrent disease and as primary treatment in selected patients. Stereotactic radiosurgery (SRS) may be used for small, residual, or recurrent lesions. Proton beam therapy is increasingly used in children to minimise radiation dose to surrounding structures.

BRAF Inhibitor Therapy

For BRAF V600E-mutant papillary craniopharyngiomas, targeted therapy with BRAF inhibitors (vemurafenib, dabrafenib) has shown dramatic tumour responses in preliminary studies, representing a promising emerging treatment avenue.  

Long-Term Management

Endocrine replacement therapy is required by most patients long-term. Obesity management, neuropsychological support, and regular visual and endocrine surveillance are essential components of ongoing care.

‍