Pituitary
Tumors and Neuro-Endocrinology
Learn more for a patient with a Pituitary Tumor - Roberta Borgo
Dr. Joseph Maroon along with their other UPMC colleagues work with the Departments of Neurosurgery, Endocrinology, Radiology, Radiation Therapy and Neuro-Ophthalmology at UPMC for the evaluation, treatment and research of patients with pituitary tumors and disorders. The Specialists who make up this multidisciplinary program are leaders in their respective fields and have combined to make UPMC one of the most comprehensive programs in the country.
UPMC is a referral center for the evaluation and treatment of pituitary tumors, pituitary adenomas, and tumors or disorders of the hypothalamic-pituitary region. Call, toll-free, at 888-234-4357 to learn more.
INDEX:
Pituitary Gland: Function and
Diseases
Treatments for Pituitary Dysfunction
- Non-surgical
- Transsphenoidal Approach
- Craniotomy
- Radiation Therapy
- Case Reports
Pituitary Gland: Function and Diseases
The pituitary gland, or master gland, is located in a bony chamber at the base of the brain It is suspended by a stalk behind the sphenoid sinus located behind the nose. The pituitary gland is made of two lobes which control the many endocrine regulated growth and many other bodily functions. The large anterior (front) pituitary lobe controls the production of various bodily hormones, and the posterior (rear) lobe governs the body's fluid balance and releases hormones made in the hypothalamus.
Frontal Lobe: The anterior lobe produces six hormones. Growth hormone, as its name implies, regulates the physical growth of most parts of your body. Prolactin stimulates the breasts to produce milk. The four other hormones made by the anterior lobe (thyroid-stimulating hormone (TSH), corticotropin (ACTH), follicle-stimulating hormone, and luteinizing hormone).
Diseases of the Pituitary
In this rare condition, the pituitary gland produces too much growth hormone, which causes excessive growth. However, an adult cannot grow taller, since the bones mature and vertical growth stops at the end of adolescence. Instead, the excess growth hormone produces acromegaly, in which your bones thicken and all other structures and organs grow larger. Overproduction of growth hormone is usually caused by a Pituitary tumor.
Acromegaly generally can occur at any time after adolescence. Usually, the first symptom is enlargement of the hands and feet, typically revealed by the tightening of a ring on the finger, or an increase in glove or shoe size.
After the hands and feet increase in size, the head and neck grow broader, and the lower jaw, brows, nose, and ears become prominent. The skin and tongue thicken, and features become generally coarser. The voice may become deeper.
Many people with this disorder experience tingling in the hands, fatigue, headaches, increased sweating, stiffness, and generalized aches. In a woman, the amount of hair on the body and limbs may increase.
In some cases of acromegaly, Diabetes mellitus develops and causes the symptoms of that disorder. If a large pituitary tumor is present, it may cause a number of other symptoms.
The longer acromegaly is left untreated, the greater the risks become. The heart continues to enlarge; High blood pressure and possibly Heart failure develop in time. In addition, a large pituitary tumor can cause serious problems with the eyesight. Also, certain cancers are more common in people who have acromegaly.
Gigantism is the same disorder as Acromegaly, except that it begins in children and adolescents instead of in adults. The pituitary gland overproduces growth hormone, usually because of a Pituitary tumor. Overproduction of this hormone causes excessive growth of all parts of the body. The main difference between the two forms of the disease is that acromegaly occurs when the arm and leg bones have stopped growing, and gigantism occurs when they are still growing so that the young person grows to giant proportions. Treatment is the same as acromegaly.
In the normal production of urine, your kidneys first filter water and other substances from your blood. The kidneys then reabsorb almost all of the filtered water, leaving urine ready to be excreted from your body. The absorbed water is returned to the bloodstream to maintain the correct concentrations of minerals, proteins, and other nutrients in blood and body fluids. If you lose a lot of body water because of fever, perspiration, vomiting, or diarrhea, for example, the kidneys reabsorb almost all of the filtered water and a small amount of concentrated urine is excreted. On the other hand, if you drink large amounts of water, the kidneys reabsorb less filtered water, and a large amount of dilute urine is produced. The process of water reabsorption is regulated by antidiuretic hormone (ADH), a hormone that is produced by the posterior lobe (rear part) of the pituitary gland. Diabetes insipidus is a disorder in which there is a deficiency of ADH, causing your body to pass large quantities of urine that contain a high percentage of water.
The most common cause of the disorder is damage to the pituitary gland from a severe head injury. The condition may also result from scarring or damage caused by an operation on the pituitary gland, or may be due to the effects of radiation therapy on the gland or on the surrounding area. Rarely, diabetes insipidus is caused by pressure on the posterior lobe of the gland from a pituitary tumor. In a form of the disorder called nephrogenic diabetes insipidus, the condition results from an insensitivity of the kidney tubules to ADH. In this condition the level of pituitary secretion of ADH is normal.
The main symptom of diabetes insipidus is that you pass large quantities of colorless urine, as much as 21 qt (20 liters) every 24 hours. This great fluid loss results in an unquenchable thirst. You will constantly be interrupted during the day and awakened at night by the strong need to urinate and drink. Potentially fatal dehydration can occur rapidly. Hormone tests to access ADH function are done by the Endocrinologist and will confirm the diagnosis.
The treatment of diabetes insipidus, is the use of a synthetic form of ADH, taken either as nose drops or by injection. The length of time you must take the drops or receive the injections is determined mainly by what has caused the disorder. If it was caused by a head injury, surgery, or radiation therapy, the defective gland may return to normal within a year, which means that you will be completely cured. If this fails to happen, you will probably have to take medication for the rest of your life. If the disorder is caused by a pituitary tumor, the tumor will probably have to be removed (see Surgical Treatments).
In the nephrogenic form of the disorder, you may only need to restrict your salt intake and take certain diuretics or other medication to help your kidneys conserve water.
Galactorrhea is production of breast milk when it is not supposed to be produced. Milk production normally occurs in a woman a few days before, and in the months following, the birth of a baby. Production at any other time in a woman, and at any time in a man, is called galactorrhea. The problem is not a serious threat to health, although it may be annoying. However, the underlying cause of galactorrhea may be a pituitary tumor, which is more serious and may lead to other symptoms.
Galactorrhea is uncommon in women and rare in men. It is usually caused by excessive amounts of the female sex hormone estrogen, which can occur during pregnancy or from taking oral contraceptives or some other medications. Another possible cause is excessive production of the hormone prolactin. Prolactin is made by the pituitary gland and stimulates milk production. Galactorrhea can also be caused by a disorder of the pituitary gland such as a tumor or may occur for no apparent reason. In women, galactorrhea is often coupled with an Absence of periods.
In order to eliminate the possibility of a pituitary tumor or another underlying disorder the Endocrinologist will probably refer you for diagnostic tests, which may include a MRI scan and blood and urine tests.
If tests fail to reveal any cause for the condition, you will probably not need any treatment. If the problem is caused by drugs, discontinuing the drugs will clear it up. If galactorrhea is caused by a pituitary gland disorder or some other disease, the Endocrinologist may prescribe hormone treatment or the drug bromocriptine to prevent milk production. If the cause is a tumor you will be refereed to a Neurosurgeon for possible surgery (see Surgical Treatments).
Other Prolactin Disorders
- Amenorrhea-Galactorrhea Syndrome; Drug-induced hyperprolactinemia; Infertility; Male hypogonadism.
Your pituitary gland is divided into two parts, the anterior, or front, lobe and the posterior, or rear, lobe. Pituitary gland tumors almost always occur in the anterior lobe.
More than 10 percent of all tumors inside the skull develop in the pituitary gland. There are two main types. Pituitary adenomas are overgrowths of one or more of the cell types in the gland. These tumors are almost always benign. Most are less than ½ in (12 mm) in size. But because they grow in a confined space they may run out of room and may damage the nerves leading from the eyes, cause headaches, and eventually cause serious brain disorders if they begin to increase further in size.
About 50 percent of all pituitary adenomas secrete abnormal amounts of the hormone prolactin. This may cause no symptoms. Or it may result in impotence, absence of menstrual periods, or Galactorrhea. Pituitary adenomas may also secrete other hormones, and this can lead to Acromegaly, Gigantism, or Cushing's syndrome. The tumor may also enlarge and press upon surrounding areas, causing other disorders. The causes of pituitary tumors are unknown. The incidence is 1 out of 10,000 people.
Types of Pituitary tumors
- Prolactinomas; Crainopharngioma, Cushing's disease; Acromegaly; Non-Secreting tumors; Recurrent Pituitary Tumors.
Common Signs and Symptoms:
Note: Symptoms are related to hormone deficiencies and pressure on intracranial structures.
- Headache
- Visual changes and loss
- Seizures
- Change or loss of menes
- Personality changes
- Impotence in men
- Enlargement of hands, feet and/or facial features
- Intolerance of heat or cold
- Excessive thirst of urination
- Skin changes
- Loss of body hair
- Breast discharge in women
- Breast enlargement in men
- Irritability
Testing:
- CT scan of Brain
- MRI Brain
- Skull X-ray
- Eye exam including Visual Fields
- Angiogram
- Endocrine function tests (blood work)
- Growth hormone
- TSH
- Thyroid Hormone
- Cortisol
- Prolactin
- ACTH
Craniopharyngioma:
The other type of tumor is called a craniopharyngioma. This type of tumor does not cause overproduction of any hormones, but it does progressively enlarge and can exert pressure either on the anterior lobe, which causes Hypopituitarism, or on the posterior lobe, which causes Diabetes insipidus. It can also press on the nerves to your eyes and, as a result, eventually cause headaches, double vision, and deteriorating sight.
- tumor located near the pituitary stalk
- often benign, but close to vital structure making surgical removal difficult
- rare, less than 5% of childhood brain tumors; average age is 7 - 12 years old
- presenting signs include vision changes, headache, , changes
- treated with combination therapy, usually surgery and radiation therapy; there is some controversy over the optimal approach to therapy
- survival and cure rates are favorable, though endocrine dysfunction may persist as well as the effects of radiation on cognition (thinking ability)
Treatments for Pituitary Dysfunction
Once recognized, these patients require Endocrinologist evaluation and blood sample will be taken to find out how much growth hormone is circulating in the body. CT or MRI scans will definitely show the extent of the tumor. Tests of your visual field (side vision) will also be required.
If the blood test shows that the growth hormone level is high and cannot be reduced with medications, and if the presence of a tumor is confirmed by CT or MRI scans, you should be treated as soon as possible. The Endocrinologist will recommend either radiation therapy or surgery.
The best form of treatment depends on a number of factors. Drugs such as bromocriptine can sometimes control a pituitary tumor and are often used first. The drug somatostatin is often used to treat acromegaly; it inhibits growth hormone, which in turn checks the growth of the pituitary tumor.
Surgical removal of the pituitary tumor may be effective in improving problems with the eyesight. Also, tumors can now be selectively removed, leaving behind only healthy tissue. Treatment often halts the progress of the disease. Cosmetic recovery is often possible, and changes in your bones and your appearance may be reversible. (see Surgical Treatments)
If all or almost all of your pituitary gland is removed or destroyed, you may need lifelong treatment with hormone replacements, such as sex hormones or thyroid hormone.
Surgical Treatments
Transsphenoidal Approach
The operation is performed to remove small tumors or cysts from the
pituitary gland. Surgery takes place after a channel is
made through the
nasal septum that divides the nostrils, and into the sphenoid sinus behind it, to
reach the pituitary chamber.
Tumors or cysts on the pituitary gland can cause vision loss, and eventual blindness, by putting pressure on the optic nerve(s) or optic chiasm. Abnormal hormone production from such tumors can also cause many other symptoms: infertility or the loss of menstrual periods in women, abnormal growth, high blood pressure, heat and cold intolerance, and other skin and body changes. Pituitary tumors are discovered, using hormone level blood tests, and MRI scans and other special X-ray testing. Using the Transsphenoidal approach is determined by the location and size of the tumor as well as the tumor consistency (i.e.. cystic or firm). Often this approach allows for complete tumor removal and leaves no visible scar due to the trans-nasal approach.
Technique
Transsphenoidal surgery is performed with the patient under general anesthesia and positioned on his back. The head is fixed in a special headrest, and the operation is monitored on a special x-ray machine (fluoroscope).
A small incision is made under the upper lip on the upper gum. Part of the septum is then removed to provide access to the sphenoid sinus cavity. A Ear, Nose and Throat (ENT) Specialist is often used to assist in this part of the operation.
A surgical microscope is brought into the operation site and part of the floor of the pituitary chamber (sella turcica) is removed and the pituitary gland is exposed.
Using suction and special curved instruments, the Neurosurgeon removes the cyst or tumor. The tissue is sent to the pathology laboratory for analysis.
Graft and closure
A small graft of muscle or fat is removed from the patient's thigh or abdomen is packed into the pituitary chamber and the floor of the chamber is reconstructed with the cartilage taken from the nasal septum earlier in the operation. The nose is then packed with special gauze.
Risk
Certain risks must be considered with any surgery: infection, excessive bleeding (hemorrhage), and an adverse reaction to anesthesia. Since pituitary tumor surgery involves the brain, other risks include meningitis and the leakage of cerebrospinal fluid (CSF) from the operation site. Due to the proximity of the optic nerves, visual blurring can occur.
Post-op Recovery
The outlook for recovery without physical limitation after this procedure is excellent. If vision loss has occurred, its progress can usually be arrested and often reversed. If the tumor is completely removed, recurrence is unlikely. Recover of hormone function is often immediate but can be delayed and may require the use of short term or long term hormone replacements.
Craniotomy
Radiation Therapy
Case Reports
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Last Updated: January 1, 2008