Craniopharyngioma

Craniopharyngiomas, also known as Rathke’s pouch tumour or craniopharyngeal duct tumours, are rare tumours that develop in the sellar and parasellar regions of the brain. It is classed as a type of central nervous system (CNS), which is made up of the brain and spinal cord.

The sellar and parasellar regions of the brain are complex, and hold and support many important structures in the brain. The sellar region of the brain is located in the centre of the cranial base (bottom portion of the skull), and is made up of the pituitary gland, a primary endocrine gland of the body, and the sella tunica, a bony pouch that the pituitary gland sits in. The parasellar region holds cavernous sinuses, suprasellar cistern, hypothalamus, and ventral inferior third valve.

In most cases, craniopharyngiomas are benignNot cancerous, can grow but will not spread to other body parts. (non-cancerous) and carry a good prognosisTo predict how a disease/condition may progress and what the outcome might be.. In very rare cases, the tumours can undergo a transformation and become malignantWhen a growth in a body part is cancerous. very serious and can grow and spread very quickly to other parts of the body. (cancerous).

Craniopharyngiomas tend to be diagnosed in children between the ages of 5-14, or in adults over 50 years old. They are generally diagnosed equally between the sexes, and can develop in anyone at any age.

Types of Craniopharyngiomas

There are two primary types of craniopharyngioma, which are categorised by the types of cells
• the smallest, living parts of the body. Cells work together to form or build the body
• a human is made up of millions of Cells
• Cells reproduce themselves to make sure a body stays working
• sometimes Cells can be abnormal or damaged and these can be cancer cells
they develop from.

Adamantinomatous Craniopharyngioma

Adamantinomatous craniopharyngiomas (ACP) are primarily found in children, and generally develop from cells in the craniopharyngeal duct. The craniopharyngeal duct is a bony channel that connects the bottom of the sella tunica to the nasopharynx (a structure in the upper most portion of the throat, behind the nose). ACPs can be solid or cystic (growth filled with liquid). They are often classified as grade
• A score that tells how quickly a tumour might spread and grow by looking at how the abnormal cells and tissue look under a microscope.
• Grade is not the same as stage.
• Grading is different depending on the type of cancer.
I (or low grade) tumours, as they develop slowly and rarely spread. While they may have a high recurrence rate, they generally carry a good prognosis.

Papillary Craniopharyngioma

Papillary craniopharyngiomas (PCP) are a less common subtype of craniopharyngiomas that are more common in adults. They generally develop from cells in the anterior portion (or front) of the pituitary gland. PCPs can be solid or cystic, and are often classified as grade I tumours. While they may have a high recurrence rate, they generally carry a good prognosis.

Malignant Craniopharyngioma

In very rare cases, a benign craniopharyngiomas can undergo a malignant transformation and become cancerous. It is not clear what causes this transformation, but a potential link to previous radiation therapy has been identified. Malignant craniopharyngiomas are not well understood, but are thought to develop more rapidly and are more likely to metastasiseFor cancer to spread or grow out of its original place.. The prognosis for malignant craniopharyngiomas may not be as good as benign craniopharyngiomas.

Treatment

When cancers are detected, they are staged and graded based on size, metastasisKnown as secondary cancer, it grows/spreads from the original/ primary cancer. (whether the cancerA disease where abnormal cells split without control and spread to other nearby body tissue and/or organs. Cancer cells can also spread to other parts of the body through the bloodstream and lymph systems. has spread to other parts of the body), and how the cancer cells look under the microscope. Staging and grading helps your doctors determine the best treatment for you. However, brain cancers are rarely staged, as they rarely spread to other parts of the body. Instead, they are generally graded from grades I-III.

Because of how rare craniopharyngiomas are, there is currently no standard grading system for this disease. Instead of grading, your doctor will recommend a treatment plan based on the following factors:

• Cancer location.
• Whether or not the cancer has metastasised.
• Your age.
• General health.
• Your treatment preferences.

Your doctor may also recommend genetic testing, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.

Treatment options for craniopharyngiomas may include:

• Surgery to remove as much of the tumour as possible, potentially including orbitozygomatic craniotomy.
• Radiation therapy.
• Chemotherapy
  • a chemical drug treatment to kill or slow-growing cancer Cells
  • these drugs are called cytotoxic drugs
  .
• HormoneA chemical made in different body parts/organs that is sent out to other parts of the body through the bloodstream. Hormones watch over and help control how other cells or organs act. replacement therapy.
• Targeted therapy.
• Clinical trials.
• Palliative careLessening pain without curing the disease..

For more information on the treatment options, please refer to the Rare Cancers Australia treatment options page.

Risk factors

Because of how rare craniopharyngiomas are, there has been limited research done into the risk factors of this disease. However, a potential link to previous radiation therapy has been identified, but more research would be required to confirm this.

Symptoms

The symptoms of a craniopharyngiomas are often related to the pressure that the tumour is putting on the brain, pituitary gland, and nearby nerves. They usually occur when the tumour reaches a certain size. General symptoms may include:

• Nausea and/or vomiting.
• Confusion.
• Mood swings.
• Behavioural changes.
• Fatigue.
• Balance difficulties.
• Increased thirst and/or urination.
• Vision changes, potentially including:
  • Blurred vision.
  • Double vision.
  • Loss of peripheral vision.
  • Blindness.
• Persistent headaches.

Craniopharyngiomas can result in decreased hormone production which may cause additional symptoms:

• Delayed growth in children as a result of growth hormone (GH) deficiency.
• Follicle stimulating hormone (FSH) or luteinizing hormone (LH) deficiency, which may result in:
  • Delayed puberty.
  • Absence of menstruation (amenorrhea).
  • Precocious puberty (rare).
• Adrenocorticotropic hormone (ACTH) deficiency, which may cause:
  • Unexplainable weight loss/loss of appetite.
  • Muscle weakness.
  • HypotensionLow blood pressure. (low bloodhello pressure).
  • DiarrhoeaWhere watery or loose faeces (stools; poo) is frequently/often released discharged from the body. Also called ‘the runs’..
  • Low blood sugar levels.
  • Dilutional hyponatremia (low sodium levels).
• Thyroid stimulating hormone (TSH) deficiency, which may cause:
  • Fatigue.
  • Lethargy (lack of energy).
  • Menstrual changes.
  • Forgetfulness.

Not everyone with the symptoms above will have cancer, but see your general practitioner (GP) if you are concerned.

Diagnosis/diagnosing

If your doctor suspects you have a craniopharyngioma, they may order the following tests to confirm the diagnosisUsing medical test results, identify and name a disease and/or condition. and refer you to a specialist for treatment.

Physical examination

Your doctor will collect your overall medical history, as well as your current symptoms. Following this, they may examine your body to check for any abnormalities.

Neurological examination

A neurological examination assesses sensory and motor functions, and can generally be done in your GPs office. The doctor may check your vision, hearing, balance, coordination, strength and reflexes, depending on the signs and symptoms you have described. Any problem that is detected in this exam can help determine which portion of the CNS needs further investigation.

Endocrine studies & blood tests

Endocrine studies involve blood and/or urine tests and imaging tests (see below) to analyse your hormone levels and detect any abnormalities. Some of these tests may include:

• General blood test to assessTo measure, look at and learn from. overall health.
• Blood tests to measure levels of:
  • Glucose.
  • Oestrogen.
  • Testosterone.
  • Prolactin.
  • GH.
  • ACTH.
  • TSH.
  • LS and FSH.
• 24-hour urine test, which measures levels of cortisol levels in your urine.
  • High-dose dexamethasone suppression test.
  • Low-dose dexamethasone suppression test.

Imaging tests

The doctor will take images of your body using magnetic resonance imagingTaking images/photos of inside body parts using magnet rather than x-ray. (MRITaking images/photos of inside body parts using magnet rather than x-ray.), a computed tomography scan (CT scanA 3-D (three dimensional) x-ray pictures that gives more information than a normal x-ray.), and/or positron emission tomography (PET scanA test that uses a radioactive drug to show a picture of how your tissues and organs are working. Also known as a positron emission tomography scan.), depending on where it is suspected the tumour is. The doctor may also look at other parts of the body and look for signs of metastasis.

Biopsy

Once the location of the cancer has been identified, the doctor will perform a biopsyTo take a small piece of body tissue and test it in a laboratory. to remove a section of tissue using a needle. In most cases, this may be done by either an excisionTo cut out or remove by cutting. biopsy, a fine needle biopsy (FNB), or a core needle biopsy (CNB).

References

• Johns Hopkins Medicine
• Mayo Clinic
• National Organization for Rare Disorders
• NCBI