The pituitary is a tiny pea-sized gland at the base of the brain. It serves as the body's "command center," producing hormones that regulate growth and metabolism as well as the actions of other glands, including the thyroid, adrenals and gonads (ovaries in women and testes in men).
Tumors arising from the cells of the pituitary gland are also known as pituitary adenomas. They are almost always benign, but can have significant side effects when they produce excessive amounts of hormones, grow large enough to affect normal pituitary function or interfere with surrounding structures, particularly the optic nerves, which are responsible for sight.
Types of Pituitary Tumors
Pituitary tumors can be divided into two broad categories:
Non-functioning tumors don't produce hormones. Symptoms are generally associated with the tumor's growth and its effects on nearby structures, including the optic nerve and other cranial nerves. Non-functioning tumors may also interfere with the pituitary gland's normal production of hormones.
Functioning tumors are those that produce excessive amounts of specific hormones, each with its own set of symptoms.
Types of Functioning Tumors
Thyroid-stimulating hormone (TSH): Tumors that overproduce this hormone cause the thyroid to release excessive amounts of thyroxine, which can lead to hyperthyroidism (overactive thyroid), although pituitary tumors are a rare cause of this condition. Symptoms include:
- Weight loss
- Rapid or irregular heartbeat
Prolactin: Prolactin stimulates breast growth and milk production in women. A pituitary tumor that overproduces this hormone is called a prolactinoma. Symptoms in women include a milky discharge from the nipples, irregular menstrual periods or the absence of menstruation. Symptoms in men include:
- Erectile dysfunction and/or impotence
- Loss of body hair
- Decreased sex drive
- Rarely, increased breast growth (gynecomastia)
Growth hormone (GH): GH regulates linear growth in children and has various effects on the body's metabolism. Tumors that overproduce GH result in acromegaly in adults and gigantism in children.
Symptoms of acromegaly include:
- Gradual enlargement of the hands, feet, jaw and/or forehead
- Coarse facial features, such as thickened skin and enlarged nose or lips
- Heart problems
- High blood pressure
- Excessive sweating
Adrenocorticotropic hormone (ACTH): This hormone stimulates the adrenal glands to produce cortisol, which plays a role in the body's response to stress and helps regulate blood pressure and heart function, among other duties. Overproduction of ACTH leads to Cushing's disease.
Symptoms of Cushing's disease include:
- Rounded "moon" face
- Weight gain, particularly in the trunk and abdomen
- Thinning of the skin
- Purple-red stretch marks
- High blood pressure
Pituitary carcinoma: In rare cases, a pituitary tumor can become cancerous and metastasize (spread) to other areas of the body. In most cases, pituitary carcinomas do produce hormones, particularly prolactin and ACTH. Symptoms would be similar to tumors producing those hormones, but may also include symptoms from the tumor's growth affecting nearby areas such as the optic nerve
Symptoms of Pituitary Tumors
Specific symptoms depend on the type of hormone secreted by a pituitary tumor. Symptoms resulting from the size of the tumor may include headaches, double vision and loss of vision due to impingement of the optic nerves.
There are few known risk factors for pituitary tumors. The only confirmed risk factor is multiple endocrine neoplasia type 1 (MEN 1), a hereditary condition that increases the chance of developing certain pituitary tumors.
Pituitary tumors can be difficult to diagnose, particularly in the early stages. Non-functioning tumors may not cause any symptoms until they grow larger, and symptoms of functioning tumors are similar to those of many other medical conditions. In fact, many pituitary tumors go undiagnosed for many years.
There are several types of tests used to diagnose pituitary tumors. The doctor will decide which tests to conduct based on the patient's symptoms.
Blood & Urine Tests
There are specific blood and urine tests for each type of hormone-producing pituitary tumor. Some tests, called stimulation tests, involve infusing a small amount of the suspected hormone into the blood and then measuring hormone levels to determine if the pituitary is functioning properly. Other tests may involve infusion of a drug that attempts to suppress hormone production.
A magnetic resonance imaging (MRI) scan is very good at detecting pituitary tumors of all sizes.
Treating pituitary tumors may involve surgery to remove the tumor, drug therapy to reduce excessive levels of hormones produced by the tumors, radiation therapy to shrink tumors or a combination of these therapies. Treatments for each patient are determined by the tumor's location, size and the specific hormones being overproduced.
Cancer is a journey that no one needs to take alone. There are many forms of support to help you through every stage: diagnosis, treatment and survivorship. Whether you meet with other cancer survivors like yourself, use complementary therapies or individual coping mechanisms, help is available in many forms. Listed below are just some of the ways to find help...and hope.
Getting together with other cancer patients in a support group is a valuable coping tool. Support groups are usually focused on a single disease or topic, such as breast cancer survivors or people coping with life-changing side effects from their cancer or cancer therapy. These groups allow participants to meet others like themselves and seek strength from each other. Most major cities and cancer hospitals offer support groups that meet weekly or monthly. There are also dozens of online support web sites or message boards for those who may not have access to a traditional meeting.
Complementary therapies are used in conjunction with cancer treatment, in an effort to reduce treatment side effects, ease depression and anxiety and help cancer patients take their mind off the negative aspects of their situation. Complementary therapies may include mind-body exercises like yoga, tai chi and Qi gong; visualization or guided imagery; using art or music as therapy and self-expression; and traditional Eastern medicine such as acupuncture.
Staying physically active as much as possible during cancer treatment has many positive benefits. Physical activity stimulates the release of endorphins, a hormone that helps elevate mood, as well as decreasing feelings of fatigue.
Exercises for cancer patients can range from simple stretches done in the bed or chair, to more active pursuits such as walking or light gardening work. However, it’s important not to push yourself too hard. Check with your doctor before attempting any physical activity to make sure you are up to it.
Many people find it helpful to keep a journal of their cancer treatment experience. It may be as simple as recording symptoms and side effects into a notebook, or may include personal emotions and opinions about what they may be going through. Journals can be private, like a diary, or shared with loved ones and even strangers.
Increasingly, people are turning to the Internet to share their cancer journey with the world at large and to seek out others with similar experiences. Many cancer patients have begun their own web log, or “blog” to publicize their battle with cancer. Twitter, a mini-blogging technology that limits posts to 140 characters, has also proven to be a helpful tool for cancer patients to keep friends updated and reach out to others.
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