Pituitary Tumour Benign

pituitary adenoma, pituitary adenomas, benign pituitary tumor

• Pituitary gland
• Brain
• Hypothalamus
• Optic nerve
• Optic chiasm
• Skull

Benign pituitary tumours are unusual growths in the pituitary gland that are not cancer and grow slowly, but they can affect your hormone levels and cause various health problems throughout your body.

Table of contents

• What is a benign pituitary tumour?
• Understanding the pituitary gland
• Types of pituitary tumours
• How common are pituitary tumours?
• Signs and symptoms
• Risk factors
• Diagnosis
• Treatment options

What is a benign pituitary tumour?

A benign pituitary tumour is an unusual growth that develops in the pituitary gland. The pituitary gland is a small organ about the size of a pea located behind the nose at the base of the brain^[1]. Most pituitary tumours are benign, which means they are not cancer. Another name for these noncancerous tumours is pituitary adenomas^[1].

Pituitary adenomas are almost always (more than 99%) benign, slow-growing masses^[4]. Most adenomas stay in the pituitary gland or in the tissue around it, and they grow slowly. They typically don’t spread to other parts of the body^[1].

Small pituitary tumours are extremely common and are present in up to 10% of the population. Most of these will never grow and do not cause any symptoms. Many are found accidentally during a routine MRI and rarely require any treatment^[4].

Understanding the pituitary gland

Your pituitary gland is often called the “master gland” or “master endocrine gland” because it plays a key role in controlling the production of hormones from other organs in your body^[4]. It’s a small gland about the size of a pea that’s joined to your hypothalamus (the base of your brain) right behind your nose^[2].

Hormones are chemicals that coordinate different functions in your body by carrying messages through your blood to your organs, muscles and other tissues^[2]. Your pituitary gland releases several important hormones, including^[2]:

• Adrenocorticotropic hormone (ACTH or corticotropin)
• Antidiuretic hormone (ADH, or vasopressin)
• Follicle-stimulating hormone (FSH)
• Growth hormone (GH)
• Luteinizing hormone (LH)
• Oxytocin
• Prolactin
• Thyroid-stimulating hormone (TSH)

The pituitary gland makes hormones that control your metabolism, stress level, growth, ovulation and menstruation in women, sperm and testosterone production in men, milk production, and urine production^[5]. Your pituitary gland also tells other endocrine system glands to release hormones^[2].

Types of pituitary tumours

Healthcare providers categorize pituitary adenomas based on whether or not they produce extra hormones^[2]:

Functioning (secreting) adenomas: These adenomas release extra pituitary hormones, which cause certain symptoms and conditions depending on the hormone it releases. Most pituitary tumours are functioning tumours^[2]. Some of these tumors cause the pituitary gland to make too much of certain hormones that control important body functions^[1].

Nonfunctioning (non-secreting) adenomas: These adenomas don’t release hormones, but they can compress nearby structures if they grow. The most common adenomas most healthcare providers diagnose are nonfunctioning pituitary adenomas^[2]. Others can cause the pituitary gland to make too little of those hormones^[1].

Healthcare providers also categorize pituitary adenomas based on their size^[2]:

Microadenomas: These adenomas are smaller than 10 millimeters or 1 centimeter. Microadenomas are less likely to continue to grow over time^[4].

Macroadenomas: These adenomas are larger than 10 millimeters. Macroadenomas are twice as common compared to microadenomas. They’re also more likely to cause lower than normal levels of one or more pituitary hormones, known as hypopituitarism^[2]. Macroadenomas typically get larger over time^[4].

How common are pituitary tumours?

Even though your pituitary gland is not technically a part of your brain, healthcare providers consider pituitary adenomas brain tumours. They represent about 10% of primary brain tumours^[2].

Pituitary adenomas can occur at any age but are more common in people in their 30s or 40s. Women are more likely to have pituitary adenomas^[2].

Pituitary adenomas make up 10% to 15% of all tumours that develop within your skull. About 77 out of 100,000 people have a pituitary adenoma, but researchers think adenomas actually occur in as many as 20% of people at some point in their lives. As many people with pituitary adenomas, especially microadenomas, are asymptomatic (have no symptoms), they’re usually never found^[2].

Signs and symptoms

Pituitary tumours often aren’t noticed or aren’t detected. In many cases, that’s because the symptoms caused by pituitary tumours are similar to those of other medical conditions. It’s also because they grow very slowly over time^[8]. Many pituitary tumours do not cause any symptoms and are found accidentally on MRI^[5].

The symptoms of pituitary adenomas can vary widely depending on several factors, including if it’s large enough to damage your pituitary gland or nearby structures (mass effect), or if it’s a functioning pituitary adenoma with symptoms based on the type of hormone it secretes^[2].

Symptoms from tumour size and pressure

Because the optic chiasm (where the optic nerves meet) sits on top of the pituitary gland, a large pituitary tumour can push on the optic nerves or chiasm and cause vision loss^[5]. Your peripheral vision is typically affected, but you may also lose central vision and colour vision in one eye if the optic nerve is compressed. Unfortunately, the vision loss can become permanent and this may limit your ability to drive or do other daily activities^[5].

Symptoms can include^[3]:

• Headaches
• Vision problems
• Nausea
• Vomiting

Pituitary hormones that impact the sex hormones, such as estrogen and testosterone, can make a woman produce breast milk even though she is not pregnant or nursing, or cause a man to lose his sex drive or lower his sperm count^[3].

Symptoms from hormone changes

Sometimes pituitary tumours cause low hormone levels (hypopituitarism), which may make you feel ill, feverish, sluggish, or fatigued. Sometimes pituitary tumours lead to an elevation in a hormone called prolactin which can result in enlargement of breast tissue and milk from the nipples. Sometimes pituitary tumours can cause elevation of growth hormone which can lead to an abnormal increase in the size of the feet, hands and head, and cause changes in facial appearance^[5].

Emergency situation: pituitary apoplexy

A rare, but urgent condition caused by rapid bleeding into the tumour is known as pituitary apoplexy. People with pituitary apoplexy develop a sudden, severe headache, often with double vision or blurred vision, and may also feel feverish or have flu-like symptoms. This may also lead to lightheadedness from very low blood pressure. If you develop these symptoms, you should call your doctor or go directly to the emergency department^[5].

Risk factors

Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn’t mean that you will not get cancer^[6].

Risk factors for pituitary tumours include having the following hereditary diseases^[6]:

• Multiple endocrine neoplasia type 1 (MEN1) syndrome
• Carney complex
• Isolated familial acromegaly

Diagnosis

To detect and diagnose a pituitary tumour, your health care provider will likely talk with you about your personal and family medical history and do a physical exam^[8].

Testing to detect a pituitary tumour may include^[8]:

Blood tests

Blood tests can show whether your body has too much or too little of certain hormones. For some hormones, blood test results that show too much of the hormone may be all that’s needed for your health care provider to diagnose a pituitary adenoma. For other hormones, such as cortisol, a blood test result that shows too much of the hormone may need to be followed by other tests. Results that show hormone levels are too low need to be followed with other tests, usually imaging exams, to see if a pituitary adenoma may be the cause of those test results^[8].

Urine tests

A urine test may be used to help diagnose a pituitary adenoma that’s making too much of the hormone ACTH. Too much ACTH leads to too much cortisol in the body and causes Cushing disease^[8].

MRI scan

A magnetic resonance imaging scan, also called an MRI scan, is a test that uses magnets, radio waves, and a computer to image your body’s soft tissues^[8].

Additional specialists

Because pituitary tumours affect many systems in your body, you may need to have different specialists who will help coordinate the best care for you. An ophthalmologist or neuro-ophthalmologist checks your central and peripheral vision, colour vision and eye movements and may order some images. An endocrinologist monitors your hormones and treats any hormonal imbalances, and may use medicine to treat your tumour. A neurologist may monitor the tumour and treat the headaches. A neurosurgeon may need to perform surgery to treat the tumour. A radiation oncologist may use radiation to treat your tumour^[5].

Treatment options

Pituitary tumours can be treated in several ways. The tumour may be removed with surgery. Or its growth may be controlled with medications or radiation therapy. Sometimes, hormone levels are managed with medicine. Your health care provider may suggest a combination of these treatments. In some cases, observation — also called a ‘wait-and-see’ approach — may be the right choice^[1].

Generally, treatment depends on the tumour’s type and size, whether it has invaded or pressed on surrounding structures, such as the brain and visual pathways, and the individual’s age and overall health^[3].

Three types of treatment are used^[3]:

• Surgical removal of the tumour: The tumour may be removed with surgery
• Radiation therapy: High-dose x-rays are used to kill the tumour cells
• Drug therapy: Medications are used to shrink or destroy the tumour. Medications also are sometimes used to block the tumour from overproducing hormones

Healthcare providers treat pituitary adenomas with surgery, medication, radiation or a combination of these therapies^[2]. Early diagnosis and treatment are key to a good prognosis^[3].