Pituitary tumors can cause hormonal problems or press on nearby structures, causing other symptoms. Learn more about pituitary tumor causes and treatment.
Your pituitary gland is sometimes called your “master gland” because it has so many functions in your body. This pea-sized gland, located at the base of the brain, produces, stores, and releases several hormones.
Pituitary tumors are usually benign adenomas and noncancerous, but they can still cause problems with your hormone levels. They can also cause issues like vision problems if they press on nearby structures.
Luckily, scientific advances now allow doctors to remove most small- and medium-sized pituitary tumors with a minimally invasive endoscopic procedure called transsphenoidal surgery instead of requiring open brain surgery. Some tumors may not require treatment or may be treatable with medications.
Pituitary tumors can be categorized into functioning and non-functioning tumors.
"Non-functioning" or "non-secreting" tumors don’t produce excess hormone levels. They can still cause health problems when they grow large and press on nearby structures. This is called the “mass effect.”
Your pituitary gland is close to the optic nerves, which relay information from your eyes to your brain. Pituitary tumors commonly press on these structures and cause vision changes.
Roughly 40 to 60 percent of people with “macroadenomas” (large versions of the most common type of pituitary tumor) have vision problems such as:
Gradual loss of peripheral vision
Double vision
Blurry vision
Other symptoms caused by the mass effect can include:
Headaches
Facial pain
Facial numbness
Low levels of certain hormones
Rarely, some people develop a medical emergency called pituitary apoplexy, where a pituitary tumor bleeds or suddenly swells. It can cause excruciating headaches, vision loss, and other neurological symptoms. Prompt medical attention is needed to avoid long-term complications.
Functioning pituitary tumors produce excess levels of pituitary hormones. They can cause all the same symptoms as non-functioning tumors if they grow large. The other symptoms they cause depend on which hormones are overproduced.
These are the most common types.
Prolactinomas are the most common type of functioning pituitary tumor, making up roughly 40 percent of pituitary adenomas. Adenomas are the most common type of pituitary tumors, making up more than 90 percent of cases.
These tumors produce too much prolactin (hyperprolactinemia). Prolactin is normally responsible for breast milk production after childbirth in women. In men, prolactin helps regulate reproductive hormones, but its precise role is less clear.
Symptoms of prolactinomas in males may include:
Women may also have vaginal dryness, pain during intercourse, changes in menstruation, nipple discharge, or infertility.
Growth hormone plays an essential role in the growth of new tissue, like bone and muscle.
In adults, tumors that produce too much growth hormone can lead to a collection of symptoms called acromegaly. Characteristic signs and symptoms include:
Abnormal hand and foot enlargement, such as an increase in ring size
Facial changes like enlargement of the forehead and brow
Deepening of your voice
Headaches
Oily skin
Arthritis
Carpal tunnel syndrome
Excessive sweating
Excess growth hormone can cause abnormal growth in adolescents, with some people reaching more than eight feet tall. Excessive height due to excess growth hormone is called gigantism.
Tumors producing too much adrenocorticotropic hormone (ACTH) stimulate your adrenal glands to produce excessive cortisol. Too much cortisol leads to a cluster of symptoms called Cushing syndrome. These symptoms have other causes as well, but when a pituitary tumor causes high levels of ACTH, the condition is known as Cushing disease.
Symptoms include:
Weight gain, especially around the abdomen
Rounding of the face (sometimes called moon face)
Upper back hump (sometimes called buffalo hump)
Thinning skin that bruises easily
Purple stretch marks
Muscle weakness
Mood changes, including depression and irritability.
Tumors that produce thyroid-stimulating hormone (TSH) are very rare, accounting for fewer than 2 percent of pituitary adenomas that secrete hormones.
They cause secondary hyperthyroidism, meaning your pituitary gland tells your thyroid gland to produce too much thyroid hormone. Symptoms may include:
Unexplained weight loss
Rapid or irregular heartbeat
Anxiety or irritability
Poor heat tolerance
Tremors
Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) regulate your reproductive function.
Tumors producing excess FSH or LH are very rare, and the most obvious symptoms are usually those related to the tumor pressing on other structures in your brain. They can also cause problems with sexual function or fertility.
Doctors often can’t identify the underlying causes of pituitary tumors. Your genetics and environmental factors likely both play a role in their development. Here’s what we do know about the most common subtypes of pituitary tumors.
Pituitary adenomas are by far the most common type of pituitary tumors, accounting for more than 90 percent of pituitary tumors. Almost all pituitary adenomas are non-cancerous. They’re subclassified into:
Microadenomas, if they’re smaller than 10 millimeters (about 0.4 inches) in diameter.
Macroadenomas, if they’re larger than 10 millimeters in diameter.
Pituitary carcinoma is a type of cancerous tumor that’s thought to be incredibly rare. It’s estimated to occur in fewer than 1 in a million people and make up fewer than 0.01 percent of all anterior pituitary tumors.
Rathke cleft cysts are non-cancerous fluid-filled sacs that develop on the pituitary gland. They’re usually asymptomatic and found incidentally with imaging for unrelated reasons.
If they’re not causing problems, they usually don’t require treatment. They’ve been reported in up to 30 percent of people in autopsy studies.
Metastatic cancer is cancer that has spread from another body part. It’s a potential complication of most types of cancer. Some types of cancer may spread to the pituitary gland.
Pituicytomas are benign tumors that originate in certain cells in the posterior pituitary gland. These tumors aren’t cancerous but can cause symptoms such as changes to your vision if they push on surrounding tissue.
Relatively few risk factors have been identified for pituitary tumors. Most develop sporadically, meaning they aren’t linked to a family history or any particular identifiable causes.
They can occur in anyone, though non-functioning macroadenomas are slightly more common in men.
A few rare genetic conditions have been identified that can increase the risk for pituitary tumors, but these conditions are responsible for only a small percentage of those tumors. They include:
Multiple endocrine neoplasia, type 1 (MEN1). MEN1 is an inherited condition that causes tumors in several endocrine glands, including the pituitary, parathyroid, and pancreas.
Carney complex. This is another rare genetic disorder that can cause tumors in various parts of the body, including the pituitary gland (often growth hormone-producing tumors).
Familial isolated pituitary adenoma (FIPA). FIPA occurs when two or more family members have pituitary adenomas, but without the other features of MEN1 or Carney complex.
Some pituitary tumors are identified incidentally during imaging for unrelated reasons. Others are identified after symptoms develop.
When you visit your healthcare provider, they usually first consider your:
Personal and family medical history
Symptoms
Results of a physical exam
If they suspect you may have a hormonal problem, they’ll likely order blood tests or urine tests to look at your hormone levels. They may also refer you to a specialist in endocrinology.
To confirm the diagnosis, you’ll need to receive imaging. The gold standard imaging test is magnetic resonance imaging (MRI). Rarely, you may need a biopsy where your healthcare provider takes a sample of your pituitary gland
If your healthcare provider identifies a tumor, they may recommend a vision test of your visual field, including your peripheral vision.
The best treatment approach for a pituitary tumor depends on which type of tumor you have, its size, and whether it's functioning or non-functioning. Treatment aims to:
Reduce tumor size
Correct any abnormal hormone production
Alleviate your symptoms
For small tumors not causing any symptoms, your doctor may simply recommend watchful waiting to monitor you for complications.
Other treatment options include the following.
Most pituitary tumors that require surgery are removed with a procedure called transsphenoidal surgery. During this procedure, your surgeon accesses your pituitary gland through your nose and the cavity behind it.
This technique is minimally invasive and leaves no external incision. It’s highly effective for removing most pituitary adenomas, but it may not be suitable for complicated cases or very large tumors.
A type of brain surgery called craniotomy may be needed for these cases. During this procedure, your surgeon will access your tumor through an incision in your skull.
Medications can help shrink some types of pituitary tumors or help reduce levels of excess hormones.
Dopamine agonists. For prolactin-secreting tumors (prolactinomas), medications like cabergoline or bromocriptine are often the first line of treatment. These drugs mimic dopamine, which naturally inhibits prolactin production.
Somatostatin analogs. Medications like octreotide or lanreotide can reduce growth hormone or TSH production and may shrink tumors in some cases.
Growth hormone receptor antagonists. Pegvisomant blocks the action of growth hormone at its receptors, easing acromegaly.
Cortisol-lowering drugs. Medications like pasireotide and mifepristone can be used to control cortisol levels if surgery isn’t successful or isn't an option for Cushing disease.
Radiation therapy may be combined with other approaches to treat some types of tumors. Radiation therapy may be administered as:
Conventional radiation therapy. Conventional radiation therapy uses high-energy X-rays over several weeks to slowly shrink the tumor and prevent its regrowth.
Stereotactic radiosurgery. This is a highly focused form of radiation that delivers a single, high dose of radiation or a few high doses to the tumor with extreme precision, minimizing damage to surrounding healthy tissue. It's often used for smaller tumors or remnants of tumors after surgery.
Unfortunately, no lifestyle changes or environmental changes have been identified as effective ways to prevent pituitary tumors. Most occur without any identifiable triggers.
If you have a family history of a genetic syndrome like MEN1 or Carney complex, get screened early to identify any potential tumors when they may be easiest to treat.
The majority of pituitary tumors are non-cancerous, but they can still cause problems like vision changes if they grow large and press on healthy brain tissue. Some tumors also release excess hormones that can cause many different problems throughout your body.
The most common type of pituitary tumor is called a prolactinoma. These growths secrete excess prolactin, which can lead to low libido, erectile dysfunction, infertility, or gynecomastia in men. Most prolactinomas respond very well to dopamine agonist therapy (such as cabergoline) and rarely require surgery.
It’s important to visit your doctor if you develop unexplained symptoms that could be related to a pituitary tumor. Your doctor can help identify the cause of your symptoms and provide you with the best treatment options.
The most common type of pituitary tumor is a pituitary adenoma, a type of non-cancerous tumor. Among tumors that produce excess hormones, prolactinomas (which produce excess prolactin) are the most frequent.
Fewer than 1 percent of pituitary tumors are malignant (pituitary carcinoma). Most adenomas are benign and slow-growing, though they can still affect hormone function or compress nearby tissues.
Yes, your pituitary gland is located very close to your optic nerves. As a pituitary tumor grows, it can press on these nerves and lead to vision problems.
Some tumors return after treatment. Your healthcare team will likely recommend regular monitoring to watch out for recurrence and restart treatment as soon as possible if necessary.
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