The pea-sized pituitary gland is located at the base of the brain and is important to the functioning of the human body.
Despite its size, the pituitary gland is responsible for producing hormones that regulate critical body organs and glands, including those that affect body tissues, such as bones and the milk-producing breast glands. Some of these glands include the thyroid gland, the adrenal glands, the ovaries, and the testicles.
Although a minority of these tumors are part of a genetic disorder, the cause of most pituitary tumors is unknown. There are no known environmental or lifestyle-related risks.
About 10,000 patients a year in the United States receive a diagnosis of pituitary tumors, which can occur at any age (including in children), but which are most often found in older adults. Almost all of these tumors are benign pituitary adenomas (ie. non-cancerous).
The actual number of pituitary tumors, however, may be much higher than the number of tumors that are found each year. Through analyses of other health problems and post-mortem exams, doctors report that as many as 1 in 4 people may have a pituitary adenoma without knowing it. Since these tumors are often small and never cause any symptoms or health problems, few of them would ordinarily be diagnosed.
Cancer of the pituitary gland is rare. Only a few hundred pituitary cancers have ever been recorded, according to the American Cancer Society. Most of those were diagnosed in older people. In the event of a cancerous tumor, however, it is treated with surgery and radiation.
Hormone-producing pituitary adenomas produce symptoms related to the hormone action of the body. Clinically non-functioning pituitary adenomas typically cause problems related to tumor growth, which exerts pressure on the surrounding brain structure.
There are many signs and symptoms of a pituitary tumor, depending on the type of tumor. These include any of the following:
Diagnosis of a pituitary tumor includes a medical history and physical exam. It may also include X-ray, MRI, and CT scans.
Pituitary tumors can also produce hormones that affect your bodily functions. If your doctor suspects a hormone-producing pituitary tumor, they may order a number of blood and urine tests to determine certain hormone levels.
In some cases, specialized tests may be ordered, such as venous sampling, which is a blood test that takes samples from both sides of the pituitary gland.
As part of your diagnosis, a doctor may also refer you for an eyesight check or test your field of vision. This is because pituitary tumors can press against parts of the optic nerve, which may impact your side vision or how well you can see.
While pituitary tumors are too rare to have a grading system, unlike some other cancers, your tumor will be diagnosed based on:
Today, doctors have a better understanding of pituitary tumors, which has greatly aided diagnosis:
In general, it is difficult to diagnose a pituitary tumor early if there are no specific symptoms or significant changes in hormone levels. In many cases, symptoms do not start until the tumor is large enough to press against an area in the brain. Thus, doctors only recommend regular screening for those who have hereditary syndromes, such as MEN1 or other gland-related syndromes, where they will monitor your blood hormone levels.
Treatments for pituitary tumors include surgery, radiation therapy and medication. Sometimes a combination of treatments is used. For example, surgery may be done to remove some of the tumor, while drugs can be used to relieve symptoms and sometimes shrink the remaining tumor.
The primary treatment, however, for most pituitary tumors is surgery. If the pituitary tumor is benign and in a part of the brain where neurosurgeons can safely and completely remove it, surgery might be the only treatment needed.
A patient will also probably need surgery if:
Radiation therapy is a treatment option in cases where not all of a tumor could be removed via surgery or there is a recurrence, or when surgery is not an option or symptoms are not relieved with medicine.
Radiation therapy can be effective but takes longer until the tumor or symptoms can be controlled. Sessions can include five times per week, for four to six weeks. Stereotactic radiotherapy is an advanced version that is more precise and requires fewer sessions, although it is only suitable for certain kinds of tumors.
Some tumors may only require medication, where hormone-controlling medicines can effectively treat symptoms and stop tumor growth or even cause the tumor to shrink.
Treatment largely depends on the type, size and growth of the tumor. At ANA, our physicians explain each option and the best course of treatment for your particular tumor.
Transsphenoidal literally means “through the sphenoid sinus.” This surgery is done through the nose and sphenoid sinus to remove pituitary tumors. Transsphenoidal surgery can be done with a microscope, endoscope, or both.
In a 2005 study with a large series of patients with pituitary adenoma, it was found that transsphenoidal surgery was an effective and safe treatment for most patients with this condition and could be considered the first-choice therapy for most of these types of tumors.
This type of surgery has a low chance of brain damage, as no part of the brain is touched. There’s also no visible scar and few side effects, although the surgery is long.
In rare cases, for example, large pituitary tumors or ones that have spread, a craniotomy may be performed, where surgery is performed through an opening in the skull.
Patients who undergo transsphenoidal surgery may experience a sinus headache and congestion for a week or two after surgery. It also increases the risk of infection in the nasal passages, so patients are closely monitored.
There may also be hormonal side effects, diabetes insipidus (increased dilute urination) and vitamin and mineral deficiencies after surgery, although these are rare. Treatment involves medication, supplements and waiting until the body adjusts to normal hormone.
In general, complications are rare after pituitary tumor surgery but if they do occur, they can be serious. Your doctor will explain signs to watch for and what to do if an issue arises.