Houston Methodist. Leading Medicine.
Houston Methodist. Leading Medicine

Pituitary Adenomas

Pituitary Adenomas 

Pituitary adenomas are common, found as often as in one percent of the population. They often cause the gland to produce too much or too little of a certain hormone. Pituitary adenomas are classified based on their size and whether or not they produce hormones.

  • Microadenomas are smaller than 1 cm (less than half an inch) in diameter.
  • Macroadenomas are larger than 1 cm in diameter.
  • About half of all pituitary adenomas are endocrine-active (functional) tumors that secrete hormones. They’re usually found when looking for the cause of a hormonal imbalance.
  • Pituitary adenomas that do not produce hormones are called endocrine-inactive or non-functional tumors. They are usually found incidentally, often when a brain scan is performed for another reason. They can also cause of vision even to blindness, which can be reversed by pituitary surgery in some cases.

  • To schedule an appointment, call 713.441.8500 or request an appointment online.

Endocrine-active (Functional) Tumors 

Excessive hormone production can have a significant impact on the body. When certain hormones are in overdrive, they can lead to serious syndromes that have far-reaching health consequences. Most pituitary adenomas secrete growth hormones, adrenocortiotropan (ACTH), prolactin, or less often, thyroid stimulating hormone (TSH). The symptoms of endocrine-active tumors depend on what hormones the tumor secretes.

Growth Hormone and Acromegaly

Growth hormone not only helps children grow, but helps adults maintain healthy bone and muscle tissue. Pituitary adenomas that increase production of growth hormone can lead to acromegaly, which means enlarged extremities. Large hands and feet are a characteristic symptom in adults. Other symptoms of acromegaly include:

  • Shoes and rings no longer fitting
  • Fingers and/or toes becoming wider
  • Hands feeling soft, like bread dough
  • Enlarged forehead, jaw, nose, lips and/tongue
  • Spaces between teeth becoming wider
  • Voice deepening in males
  • Skin changes including skin tags, oily skin and excessive sweating
  • Carpal tunnel syndrome (due to enlarged wrist tissue)
  • Arthritis
  • Sleep apnea
  • Headaches

Because the physical changes take place slowly, it can take years before acromegaly is diagnosed. Long-term or untreated acromedgaly can lead to:

  • High blood pressure
  • Type 2 diabetes
  • Heart disease, including heart failure from an enlarged heart
  • Thyroid cancer
  • Colon polyps

Acromegaly is a life threatening disorder. If you are over 45 years of age, patients with acromegaly have a death rate that is twice that of a matched population that does not have the disease. Deaths are due to primarily to heart attacks and stroke.

Although rare in children, pituitary tumors that increase growth hormone in children can lead to gigantism. This means that one grows very tall, sometimes over 8 feet. The difference is that if you have a growth hormone secreting tumor before puberty, your growth plates are open and your height increases dramatically.

To schedule an appointment, call 713.441.8500 or request an appointment online.

ACTH and Cushing's Disease

The pituitary produces adrenocorticotropic hormone (ACTH), which triggers the adrenal glands, located just above the kidneys, to produce cortisol. Cortisol is a body steroid that helps regulate blood pressure, cardiovascular function, and the metabolism of proteins, carbohydrates and fats. It also reduces the body’s inflammatory response, helps insulin break down sugar for energy and helps the body respond to stress. Pituitary tumors can occur in cells that make ACTH, and these cells then make too much of this substance. This leads to too much cortisol in the body. When this happens, it creates a collection of symptoms known as Cushing’s Disease. Although fairly rare, Cushing’s Disease affects five times more women than men. It’s most common among adults ages 20 to 50. Symptoms include:

  • Upper body obesity with thin arms and legs
  • Collection of fat between the shoulders (buffalo hump)
  • Rounded face (sometimes called moon face)
  • Increased fat around the neck
  • Severe fatigue
  • Weak muscles
  • Bone pain
  • Thin and fragile skin that bruises easily
  • Purple marks on the abdomen, thighs, buttocks, arms and breasts
  • Women grow more hair on their faces, necks, chests, abdomens and thighs
  • Menstrual cycles may be irregular or stop
  • Men have lower libido (sex drive) and fertility
  • Thin, weakened bones resulting in rib and spine fractures from everyday activities
  • Obesity and slow growth in children
  • Mental changes


Cushing's Disease is also associated with high blood pressure that’s often hard to control, diabetes, irritability, anxiety and depression. Let untreated, this is a fatal disorder.

Prolactinoma

Some pituitary adenomas produce excess prolactin (hyperprolactinemia), which decreases estrogen levels in women and testosterone levels in men. This disrupts the reproductive system and can lead to infertility. The tumor’s location can impair vision, which many times is the first symptom people notice.

General prolactinoma symptoms:

  • Low bone density
  • Low levels of other hormones (hypopituitarism) due to pressure from the tumor
  • Low sex drive
  • Headaches
  • Infertility
  • Vision problems

Because prolactinoma affects sex hormones, women and men may have different symptoms. Prolactinoma symptoms in women:

  • Irregular menstrual cycle or no periods at all
  • Milky discharge from breasts when not pregnant or breast-feeding
  • Vaginal dryness, leading to painful sex
  • Excessive face and body hair
  • Acne

Prolactinoma symptoms in men

  • Erectile dysfunction
  • Enlarged breasts


Men tend not to notice symptoms until the tumor is large, and causes headaches or vision problems.

Thyroid Stimulating Hormone Tumors
These tumors cause the pituitary to excrete too much TSH, which causes the thyroid to produce too much thyroid hormone. TSH-secreting tumors are rare, but people who have them will have the symptoms of an overactive thyroid (hyperthyroidism), which include:

  • Unexplained weight loss
  • Rapid or irregular heart beat
  • Shaking or tremors
  • Increased appetite
  • Sweating, or feeling hot
  • Frequest bowel movements
  • Trouble falling asleep
  • Anxiety
  • Enlarged thyroid (lump in the front of the neck)


To schedule an appointment, call 713.441.8500 or request an appointment online.

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Endocrine-inactive (Non-functional) Pituitary Tumors 

Endocrine-inactive tumors (also called non-functional or non-secreting tumors) do not secrete hormones, or sometimes secrete a defective hormone that has no endocrine effects. Because these types of pituitary adenomas do not alter hormone levels, they are usually found only after they’ve grown large enough to exert pressure on surrounding tissues or structures, where they may:

  • Cause headaches that get progressively worse.
  • Press on the optic nerves, causing a loss in peripheral vision (the extreme left or right sides of what you see) or double vision.
  • Grow large enough to cause severe vision loss, including blindness.
  • Cause increased pressure in the brain.
  • Very large tumors may press on other areas of the brain and cause problems with memory, weakness or numbness.


To schedule an appointment, call 713.441.8500 or request an appointment online.


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Treating Pituitary Adenomas 

Specialists at Peak Brain & Pituitary Tumor Center at Houston Methodist offer many treatment options to remove or shrink pituitary adenomas. Treatment may include:


To schedule an appointment, call 713.441.8500 or request an appointment online.

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