Pituitary Tumors:What You Need to Know
The pituitary gland is a small, pea-sized organ in the brain. Most pituitary tumors are benign.
Symptoms vary depending on the type of tumor and the affected area of the pituitary gland.
Your health care provider may order blood and urine tests, CT scan, MRI, or biopsy to diagnose the tumor.
Treatment may include surgery, radiation therapy, or medication.
What is a Pituitary Tumor?
A pituitary tumor is an abnormal growth of cells in the pituitary gland, which is the main hormone-producing gland in the body. Hormones are chemical substances the body produces that control and regulate certain cells or organs.
About the size of a pea, the pituitary gland is located in the center of the brain behind the nose and eyes. A tumor in the pituitary gland can disrupt the normal balance of hormones in the body and cause illness.
About 10 percent of all primary brain tumors are pituitary tumors, and only a very small number of pituitary tumors are malignant (cancerous).
However, because of the location of the pituitary gland, at the base of the skull, they can cause problems since they grow upward. Eventually, some pituitary tumors will press against the optic nerves, causing vision problems.
Many pituitary tumors are small, do not cause health problems and may never need treatment. Almost all pituitary tumors can be treated, usually through medications and surgery.
What Causes Pituitary Tumors?
There is no obvious cause of pituitary tumors. Some might be related to stimulation from the hypothalamus, a part of the brain that signals the pituitary gland to make hormones.
About one to five percent of pituitary tumors occur within families. Certain rare inherited conditions can mean a higher risk of pituitary tumors.
One such disorder is multiple endocrine neoplasia type 1 (MEN-1), which causes tumors in the endocrine glands (which secrete hormones into the bloodstream and include the pituitary gland) and the first part of the small intestine. Carney complex is another condition that causes several types of tumors, including in the pituitary gland.
Types of Pituitary Tumors
Pituitary tumors include:
Signs and Symptoms of Pituitary Tumors
A pituitary tumor causes symptoms by pushing on brain tissue surrounding the tumor or through excessive or impaired hormone production. Some pituitary tumors may not cause any symptoms.
Pituitary tumors are not usually diagnosed until symptoms appear. The most common symptoms include:
Other symptoms include:
Production of breast milk by a woman who has not given birth
Accelerated or stunted growth in a child or teenager
Growth of the hands, feet, forehead and jaw in adults
Development of a round face, a hump between the shoulders or both
Feeling very tired
Diagnosis of a Pituitary Tumor
Diagnosis of a pituitary tumor involves:
A physical exam: This includes questions about symptoms the person is experiencing, personal and family health history, physical exam, and tests of vision, and reflexes.
Brain imaging: A magnetic resonance imaging (MRI) scan, which uses computers to create detailed images of the brain and pituitary gland, is the most common scan used to diagnose pituitary tumors. People with a pacemaker or who cannot have an MRI scan for another reason will receive a computerized tomography scan (CT or CAT scan) instead. A CT scan also uses computers to create detailed images of the brain and pituitary gland.
Blood and urine tests: An endocrinologist will perform blood or urine tests to determine the levels of hormones in the body. If the person has abnormal amounts of specific hormones, this will help doctors diagnose a specific syndrome.
: This is a rarely needed surgical procedure to remove a small sample of the tumor for examination under a microscope.
If a pituitary tumor is diagnosed, the doctors will determine how serious it is.
Treatment for Pituitary Tumors
The treatment for a pituitary tumor will depend on many factors, including:
The location of the tumor
Whether the pituitary tumor produces excessive amounts of a specific hormone
The person’s general health and preferences regarding potential treatment options
Because having a pituitary tumor can affect many different organs and systems in the body, doctors from several medical specialties will work together to develop a customized treatment plan for each person.
Observation means seeing a neurosurgeon or endocrinologist and having imaging tests performed periodically. Treatment may be necessary later, for example, if the pituitary tumor grows or symptoms worsen.
Surgery for Pituitary Tumors
Surgery is the most common treatment for pituitary tumors. If the pituitary tumor is benign and in a part of the brain where neurosurgeons can safely completely remove it, surgery might be the only treatment needed.
Surgery may be recommended if the tumor:
Is producing hormones that medication cannot control
Is causing health problems by pressing on the pituitary gland or other parts of the nervous system
Is still growing despite previous treatment with medication or surgery
The most common types of surgery for pituitary tumors are:
Medication (Drug Therapy) for Pituitary Tumors
Medication (drug therapy) is very effective for treating some hormone-producing pituitary tumors. The medication can stop a tumor from producing excess hormones or shrink it so it does not press on the pituitary gland or other parts of the nervous system.
Medications (drug therapy) commonly used to treat pituitary tumors:
Bromocriptine and cabergoline may work for pituitary adenomas called prolactinomas, which produce too much of the hormone prolactin. These medications can treat prolactinomas by decreasing prolactin secretion and often shrink the tumor.
Somatostatin analogs (for example, Lanreotide®, Octreotide®) are recommended for pituitary adenomas that produce excess growth hormone. These drugs decrease growth hormone production and may decrease the size of the tumor. They can also be used to treat pituitary adenomas that produce excess thyroid hormone. Pegvisomant (Somavert®) blocks the effect of excess growth hormone on the body.
Ketoconazole (Nizoral®) addresses pituitary tumors that cause a round face, hump between the shoulders or other symptoms of the body producing too much cortisol, a natural steroid hormone. This medication decreases cortisol secretion but does not shrink the tumor or stop hormone production.
If a pituitary tumor has decreased the body’s ability to produce the necessary hormones, or if hormone production is too low after surgery, hormone replacement therapy may be continued at home.
Radiation Therapy for Pituitary Tumors
Doctors administer radiation therapy for pituitary tumors that:
Cannot be completely removed safely
Do not shrink with medication
Are located in areas of the brain where surgery is unsafe
Recur after surgery
Radiation therapy for pituitary tumors works gradually, and so it may take several months or years to control a pituitary tumor’s growth or stop hormone production.
Two types of radiation therapy are used to treat pituitary tumors:
After surgery or radiation therapy, medication may be required to replace or control the balance of hormones in the body. Some people might be able to stop taking hormone medication eventually.
The doctor will follow up by performing MRI scans and blood and urine tests after treatment to determine how well the pituitary gland is working.