Pituitary Tumours

Pituitary tumours form in or on the pituitary gland. They are not officially classified as brain tumours but fall within the category of endocrine (hormone) system tumours: which means that these patients get extra care. Part of the multi-disciplinary team looking after somebody with this type of tumour would therefore include a neuro-endocrinologist who specialises in supporting the balance of hormones, as well as the same people who would care for someone with a brain tumour.

What is a pituitary gland?

The pituitary gland is a small structure, about the size of a pea, attached to the base of the brain behind the nose. It lies in a small hollow in the skull, just below the eye, where it is protected by a part of the skull called the sphenoid bone.

Just above the pituitary gland lies the hypothalamus, which produces hormones that control when the pituitary produces and releases hormones of its own. Together they orchestrate the delicate balance of hormones made by glands throughout the body including thyroid, ovaries and testes. The pituitary gland directly produces hormones that control the function of certain organs such as the breasts, uterus and kidneys. The pituitary therefore influences many processes including growth, development, and reproduction.

Pituitary Adenomas

The majority of tumours that arise within the pituitary gland are classified as pituitary adenomas. Pituitary adenomas are benign, slow-growing tumours. Most pituitary adenomas are microadenomas which are small tumours less than 1cm in diameter, although a few patients have macroadenomas, which are larger.

Some types of adenomas release extra hormones into the bloodstream, hence causing symptoms. However not all adenomas produce hormones: about one third of those diagnosed are classified as non-functioning or null cell adenomas, and these cause symptoms because they grow and place pressure on the pituitary gland and surrounding brain tissue.

Is a pituitary adenoma benign or cancerous?

Pituitary adenomas are generally considered to be benign, although some are more aggressive than others. They do not spread to other parts of the brain, but remain within the pituitary gland.  

How common are pituitary adenomas?

- Pituitary adenomas are the third most common tumours found within the skull in adults, making up about 10% of the total number.

- They are discovered in approximately 77 out of 100,000 people

- It is possible that they actually occur in as many as 20% of people at some point in their lives, but cause no symptoms or are so small that they are never found.

- Pituitary adenomas can occur at any age but are more common in people in their 30s or 40s and rare in those under 20 years old. 

- Women get adenomas more often than men.

What are the symptoms of a pituitary tumour?

Because the pituitary gland has such varied functions, a tumour can be difficult to diagnose because the symptoms will differ between patients. The symptoms are often due to changes in the levels of the hormones that the gland produces, and there is a range of reasons why those hormone levels may fluctuate and cause symptoms, hence delaying the diagnosis of a tumour. 

Symptoms caused by hormonal fluctuations include:

  • Delayed puberty in children
  • Changes in menstrual periods or early menopause in women
  • Increased or decreased sexual drive
  • Extreme growth spurts in both children and adults, particularly of either hands or feet
  • Unexplained weight gain or loss, sometimes combined with a loss of appetite
  • Extreme tiredness and/or listlessness
  • Personality changes such as hostility, depression, anxiety
  • Low blood pressure
  • Loss of muscle mass in adults
  • Easy bruising of the skin, often combined with muscle weakness
  • Changes in the sense of smell
  • Vision problems such as blurring, double vision, loss of peripheral vision
  • Headaches
  • Nausea and vomiting
  • Cushing’s disease, caused by too much adrenocorticotropic hormone (ACTH) being released, which triggers the adrenal glands to make too much of the stress hormone, cortisol
  • Hyperthyroidism, caused by too much thyroid stimulating hormone (TSH) being released, giving rise to symptoms such as rapid heartbeat and an increased metabolic rate

    If the tumour is large enough to press upon surrounding brain tissue, the symptoms may be very similar to those of other brain tumours found in this part of the brain.

Frequently Asked Questions

How is a pituitary tumour diagnosed?

The most reliable way to diagnose any kind of brain tumour is initially by an MRI scan and then by taking a biopsy (a small sample of the tumour, removed during neurosurgery) for analysis in a laboratory. The presence of a pituitary tumour can also be indicated by tests that measure the levels of specific hormones within the blood.

What causes a pituitary tumour?

Research is underway to understand more about the genetic mutations that influence the development of this tumour type. Most seem to arrive with no clear cause, although there are a few cases of pituitary tumours appearing within a family group.

There are certain hereditary conditions which give an increased risk of pituitary tumours, the most common one being multiple endocrine neoplasia, type 1 (MEN 1), for which there is a genetic test to establish if this is the case.  MEN I causes multiple tumours to arise in various glands of the endocrine system, not just the pituitary gland. 

What are the end of life symptoms of Astrocytoma?

As astrocytoma progresses, especially in advanced stages or high-grade tumours, individuals may experience end-of-life symptoms. These symptoms can vary depending on factors such as the tumour location, size, and individual variations. It's important to note that each person's experience may differ, and not all symptoms may be present. Here are some common end-of-life symptoms associated with astrocytoma:

Neurological Decline: Astrocytomas can cause progressive neurological decline as the tumour affects brain function. This may manifest as worsening cognitive impairment, confusion, memory loss, difficulty speaking or understanding, and changes in behavior or personality.

Seizures: Seizures are common in individuals with astrocytoma. As the tumour progresses, seizures may become more frequent and severe, sometimes leading to status epilepticus, a prolonged seizure activity that requires immediate medical attention.

Headaches: Headaches are a common symptom of astrocytoma. They may become more intense and resistant to treatment as the tumour progresses. The headaches may be accompanied by nausea and vomiting.

Increased Intracranial Pressure: As the tumour grows, it can cause an increase in intracranial pressure. This can result in symptoms such as persistent headaches, drowsiness, confusion, changes in vision, difficulty with balance and coordination, and in severe cases, coma.

Decline in Physical Functioning: Astrocytomas can affect motor function, leading to weakness, difficulty with movement, coordination problems, and paralysis in some cases. This decline in physical functioning can affect mobility, self-care, and overall independence.

Fatigue and Weakness: Advanced astrocytoma can cause profound fatigue and weakness. Individuals may experience extreme tiredness, reduced energy levels, and a general decline in physical strength.

Changes in Sleep Patterns: Individuals with astrocytoma may experience disruptions in their sleep patterns. This can include difficulty falling asleep, staying asleep, or excessive sleepiness.

Loss of Appetite and Weight Loss: Loss of appetite and unintentional weight loss are common in end-stage astrocytoma. The tumour's effects on the brain and changes in overall health can lead to reduced interest in food and difficulty with eating.

Difficulty Swallowing and Speaking: As the tumour affects the areas of the brain responsible for swallowing and speaking, individuals may experience difficulty swallowing (dysphagia) and speech problems (dysarthria).

Respiratory Distress: In advanced stages of astrocytoma, individuals may experience respiratory symptoms such as shortness of breath, labored breathing, or irregular breathing patterns.

It's important to note that the presence of these symptoms does not necessarily mean immediate end-of-life is imminent. However, if you or a loved one are experiencing these symptoms or have concerns about end-of-life care, it's essential to consult with a healthcare professional, such as a palliative care specialist or hospice team. They can provide guidance, support, and appropriate interventions to manage symptoms and improve quality of life during this stage.

How can we find a cure for pituitary brain tumours in the UK?

Research we are funding across all of our dedicated Research Centres will help lead towards finding a cure for a wide range of brain tumours.

Our team at the University of Plymouth Low-Grade Brain Tumour Research Centre are researching a number of molecular pathways that influence immune system function, tumour metabolism and tumour growth in a range of low-grade brain tumours in children and adults. 

The team of research and clinical experts in our Research Centre at Imperial College, London, are studying the way in which the ketogenic diet works in brain cancer, which may have the potential to influence a wide range of brain tumours.

Pioneering research at our Brain Tumour Research Centre at Queen Mary University of London is focused on using GBM stem cells to help develop unique, patient-specific treatments. Their findings are expected to translate into other types of adult and paediatric brain tumours.

We also fund BRAIN UK at Southampton University, the country’s only national tissue bank registry providing crucial access to brain tumour samples for researchers from all clinical neuroscience centres in the UK, effectively covering about 90% of the UK population, and an essential component in the fight to find a cure for pituitary brain tumours.

Treatment options for pituitary tumours

The treatment options for pituitary adenomas include surgery, drugs and a form of radiotherapy called stereotactic radiotherapy.  

Neurosurgery for pituitary adenomas

Endoscopic transsphenoidal pituitary adenoma resection is carried out under general anaesthetic.  An endoscope (a tiny light and camera on a long tube) is inserted into the nostril towards the base of the tumour. Surgical instruments are then inserted next to the endoscope through the same nostril. The tumour is removed and the bony floor of the space occupied by the pituitary is closed.
Patients usually undergo this procedure via the right nostril, however surgery is sometimes done via the left nostril, depending on the location of the tumour.

Stereotactic radiotherapy for pituitary adenomas

Stereotactic radiotherapy (SRT) is sometimes used for small brain tumours, usually those that are only 3-4cm across and in an easily accessible part of the brain, relatively close to the skull. It consists of very precisely focused gamma ray or x-ray beams at higher doses than are used in standard radiotherapy. 
The advantage of this treatment is that is can be more closely targeted at a brain tumour than standard radiotherapy and surrounding healthy tissue can be spared, hence reducing the side effects of the treatment.


Chemotherapy for pituitary adenomas

Certain types of pituitary adenoma exhibit more aggressive behaviour than others, and these would be treated with chemotherapy drugs. However because this is so unusual, there is no standard chemotherapy treatment.  The choice of drugs is therefore guided by the genetic profile of the tumour in each individual case, although temozolomide (Temodar) is likely to be considered.