Craniopharyngioma

Definition

Craniopharyngioma is a cancer which arises in the pituitary gland, in tissue originally found in the embryo. One of the most common childhood brain cancers, it is also sometimes called a Rathke's pouch tumor or a suprasellar cyst.

Description

Craniopharyngioma is the second most common type of childhood brain tumor, accounting for almost 10% of all brain tumors in children. This cancer has very little tendency to spread to other parts of the body. It readily invades local tissues, however, and since it occurs deep within the brain, invasion of local tissues alone can result in serious illness or even death.

The pituitary gland produces many hormones that play critical roles in the development and regulation of the body. Because this cancer arises in the pituitary gland, it often results in deficiencies of the various hormones that the pituitary gland produces. The tumor can be either solid or cystic or mixed, and most (up to 90%) of craniopharyngiomas contain calcium deposits, an indication of diseased tissue readily observable on x rays.

Demographics

The large majority of craniopharyngiomas are childhood tumors. The median age at diagnosis is eight years; peak incidence is between the ages of six and eleven. Almost 70% of all craniopharyngiomas occur before the age of 20, although a small peak occurs after the age of 50. Diagnosis before the age of two is very rare. Girls and boys and all races are affected equally.

Causes and symptoms

The cause of craniopharyngioma is not really understood, although it is believed to be primarily a congenital illness. Nests of embryonic cells exist in a part of the pituitary gland known as Rathke's pouch. In craniopharyngioma, these nests appear to contain cancerous cells which, over time, multiply and become a tumor.

The symptoms of craniopharyngioma can be divided into two categories. Some are nonspecific symptoms which occur because of increased pressure within the skull; some result from deficiencies of the hormones that the pituitary gland normally produces. Any individual patient may have various combinations of symptoms and both the number of symptoms and the severity of the symptoms typically increase over time. Nonspecific symptoms of increased intracranial pressure include:

• headache
• visual disturbances
• irritability
• personality changes
• mental disturbances

Symptoms that can result from hormone deficiencies include:

• diabetes
• growth retardation
• sexual dysfunction (in adults)

Diagnosis

Most patients seek medical attention because of headaches or visual disturbances, failure to match normal growth patterns (due to a deficiency of growth hormone), or symptoms of diabetes. If (after other causes of symptoms are ruled out) a craniopharyngioma is suspected, usually some kind of imaging technique is performed. Traditional x rays reveal an enlargement of the space at the base of the skull where the tumor is typically found, and will also show calcification of cancerous cells. Computed tomography (CT scan or CAT scan) may show calcification that does not show up on x rays and also shows whether the tumor is cystic or solid in nature. Magnetic resonance imaging (MRI) can show how much the tumor has invaded the surrounding tissues.

Often the amounts of pituitary hormones in the blood are measured as well. Measurements may be made of gonadatropins (hormones which regulate reproduction), thyrotropin (a hormone that regulates the thyroid gland), growth hormones (regulates growth), corticotropin (a hormone that regulates carbohydrate metabolism, vasopressin (a hormone that regulates water retention), or prolactin (a hormone that regulates milk production in mothers of infants).

Treatment team

As the understanding of cancer grows and new treatment approaches are developed, the complexity of cancer treatment also increases. Today, a multidisciplinary approach to cancer treatment is considered necessary for effective patient care. Since craniopharyngioma is a neuroendocrine tumor that occurs deep in the brain and mainly in children, optimal treatment requires a particularly complex and sophisticated team of health professionals. The types of people who may be involved in treating or caring for a patient with craniopharyngioma and their family typically include oncologists (pediatric), pathologists (neuropathologists), radiation oncologists, radiation technicians, psychiatrists, oncology social workers, nutritionists, home health care providers, endocrinologists, rehabilitative specialists, and neurosurgeons. The surgeon, specifically, should be a pediatric neurosurgeon, as these specialists have been shown to provide better long-term outcomes than general neurosurgeons.

Clinical staging, treatments, and prognosis

Standard treatment for craniopharyngioma consists of surgical removal of as much of the tumor as is readily accessible, followed by radiation therapy . Although total removal of the tumor yields the best odds of survival, the location in which this cancer occurs (and the fact that these tumors are typically covered by a thick membrane that adheres tightly to surrounding tissues) can make total removal difficult. Attempts to remove the tumor completely, therefore, often result in significant and unacceptable side effects. A better quality of life, and therefore better overall outcome, is obtained through partial removal of the tumor followed by radiation therapy. This is now generally accepted as the best treatment approach.

Chemotherapy is not routinely used for treatment of craniopharyngioma, although some medications are commonly used to treat symptoms. Drugs that decrease inflammation and reduce the probability of convulsions may be given preoperatively to make surgical removal of the tumor safer. Hormone replacement therapy may be necessary if the cancer, occurring in the pituitary gland, causes serious hormone deficiency problems.

Therapies that are not routinely used but have shown some promise include internal placement of radioactive material and improvements in surgical techniques, including stereotactic surgery, which utilizes a radioactive "gamma knife" for excision of the tumor.

Since this type of cancer does not demonstrate a tendency to spread to remote areas of the body, staging or grading systems are not usually used. Factors that improve survival are complete removal of the tumor (although this often results in greatly decreased quality of life), the size of the tumor at diagnosis, a cystic rather than solid nature of the tumor, and an age of at least five years old at diagnosis. Unfortunately, most patients who survive have significant remaining illness, and predicting how much function may be lost is as important in this cancer as prognosis of survival. It is important to remember, especially with regards to extent of functional capacity to be expected, that the physician's prognosis is only an educated guess, and that positive thinking can contribute significantly to a better quality of life.

Alternative and complementary therapies

Alternative and complementary therapies are treatments which are not traditional, first-line therapies like surgery, chemotherapy and radiation. Complementary therapies are those that are meant to supplement traditional therapies and usually have the objective of relieving symptoms or helping cancer patients cope with the disease or traditional treatments. Alternative therapies are nontraditional treatments which are chosen instead of traditional treatments in an attempt to cure the disease. Alternative therapies have typically not been proven to be effective in the same way that traditional drugs are evaluated, in studies called clinical trials , and are usually not recommended for use with children.

Common complementary therapies that may be employed by cancer patients include aromatherapy, art therapy, massage, meditation, music therapy, prayer, t'ai chi, and yoga or other forms of exercise, which reduce anxiety and can increase a patient's feeling of well-being. Many patients also take high doses of vitamins and other nutritional supplements, especially A, C, E, and selenium, which are thought to act as antioxidants . Any physical activities or nutritional supplements (especially when treating a child) should be discussed with then patient's physician.

Numerous alternative therapies exist in cancer treatment. Special caution must be used, however, when considering alternative therapies for children's cancers. Although alternative treatments, by definition, have not been proven effective by scientific methods, some brain tumor patients believe that the use of alternative therapies has been beneficial. Some alternate therapies include:

• Laetrile, a product of apricot seeds, contains a form of cyanide that proponents believe may be released by tumor enzymes and act to kill cancerous cells. Laetrile is not approved by the Food and Drug Administration for use in the United States. The National Cancer Institute sponsored two studies of laetrile in the late 1970s and early 1980s, but concluded after the second study that no additional research was necessary.
• Vitamin E, melatonin, aloe vera, and a compound called beta-1, 3-glucan are reported to stimulate the immune system. Some practitioners believe that natural substances like garlic, ginger, and shark cartilage shrink tumors, although how they are supposed to work is not really defined.
• Antineoplastons are believed by some to be another alternative approach to a cancer cure. Antineoplastons are small proteins which may act as molecular messengers and which may be absent from the urine and blood of many cancer patients. The therapy is based on the idea that replacing these proteins may have beneficial effects. However, the National Cancer Institute proposed phase II clinical trials, and protocols were developed, but the trials never got underway on a large scale because of lack of patient participation. The National Cancer Institute draws no definitive conclusions about the treatment's effectiveness due to lack of clinical trials.

Coping with cancer treatment

Children have special needs when coping with treatment, depending on their age. Some comprehensive resources are available about how families can cope with cancer diagnoses, but some coping strategies are summarized here. Very young children need affection, soothing, time to play, reassurances, while toddlers have these same needs, but also may need to be taught how to express their anger or frustration, and simple explanations about what is happening. School-age children may enjoy a little more involvement in their treatment plan, and will need empathy about missing school and activities. They may benefit from drawing or keeping a journal, communicating with friends, and, if possible, a little physical activity each day. Adolescents have similar needs, but also may want to keep some thoughts and feelings private, and also may have more complex spiritual concerns along with feelings of anger and frustration. The siblings and parents of the child with cancer will have needs and concerns and will need to adopt coping strategies as well. The patient's treatment team can help point the family to helpful resources.

Treatment of craniopharyngioma commonly includes surgery and radiation therapy. Although the use of radiation therapy in addition to surgery has improved the quality of life for craniopharyngioma patients, treatments unavoidably result in damage to some healthy tissues and other undesirable side effects.

Fatigue is a very common side effect of radiation therapy. Patients should expect to be very sleepy and therefore to cut back on activities, allowing plenty of time for resting and letting the body heal. It is also important to try maintain a well-balanced, nutritious diet. Patients should avoid as much extra stress as possible and should limit visitors, if needed, to avoid being overtired.

Another problem for those undergoing radiation therapy is dry, sore skin in the area being treated. (Radiation does not hurt during treatment and does not make the person radioactive.) Skin in the treatment area is essentially "burned" and may blister and peel, becoming painful. Patients with fair skin or those who have undergone previous chemotherapy have a greater risk of more serious reactions. Dry, itchy or sore skin is temporary, but skin in the treatment area may remain more sensitive to sun exposure, so a good sunscreen should be used whenever affected skin is exposed to sunlight.

Radiation therapy requires a substantial level of commitment from the patient in terms of time and emotional energy. Fear and anxiety are major factors in coping with cancer in general and these cancer treatments specifically. The feelings are completely normal. Some patients find that concentrating on restful, pleasurable activities like hobbies, prayer, or meditation is helpful in decreasing negative emotions. It is also very important that patients have people to whom they can express their fears and other negative emotions. If friends or family members are unable to provide this to patients, support groups may help to provide an environment where fears can be freely expressed and understood.

Clinical trials

Although numerous clinical trials are in progress which evaluate treatments for childhood brain tumors, few of these are specifically concerned with craniopharyngioma. Most clinical trials for childhood brain tumors are evaluating new medications or new chemotherapy combinations. Although some of these may prove effective against craniopharyngiomas, chemotherapy at this time is not considered an appropriate approach to treatment of this disease. Some new therapies with potential value for cranipharyngioma patients include new forms of drug delivery, including liposomes, and immune-based therapies like monoclonal antibodies . In addition, new refinements of surgical techniques, including MRI-assisted surgery and stereotactic surgery, including the bloodless "gamma knife" surgery, are being evaluated. A clinical trial evaluating a pharmaceutical therapy for a common side effect of surgical treatment of craniopharygioma, hypothalmic obesity, is ongoing.

Prevention

Craniopharyngioma is believed to be a congenital disease, and there is no known way to prevent this cancer.

Special concerns

This tumor is characterized by various diseases related to hormone deficiencies which may arise as the result of the tumor itself or as the result of either surgical or radiation therapy. The tumor may cause problems related to hormone deficiencies, especially diabetes or growth retardation, and these are often the reason that medical attention is first sought. Craniopharyngioma patients may also experience sleep disorders, changes in personality, and mental disturbances. In addition, treatment for craniopharyngioma can create a condition called hypothalmic obesity, in which a patient steadily gains weight although eating patterns may not have changed. Although many of these problems may significantly improve with time, care of a family member with a brain tumor is a significantly stressful experience for caregivers, which creates a huge strain on normal family life.

As mentioned, childhood cancers create unique concerns for the children diagnosed and their families. Parents and siblings, as well as the cancer patient, all have emotional issues to address, in addition to everyday concerns, such as social development, friends, and school. Hospital staff and social workers can help direct a family to useful resources for support. Support groups for craniopharyngioma patients and for parents of craniopharyngioma patients offer patients and parents a place to discuss their fears and concerns with other people who have been impacted by this disease.

Resources

BOOKS

Abeloff, ed. Clinical Oncology. New York: Churchill Livingstone.

Bracken, Jeanne Munn. Children with Cancer: A Comprehensive Reference Guide for Parents. New York:Oxford University Press, 1986.

Buckman, R. What You Really Need to Know About Cancer. Baltimore: Johns Hopkins University Press, 1999.

Cook, Allan R., ed. The New Cancer Sourcebook. New York:Omnigraphics, Inc., 1996.

Fromer, Margot Joan. Surviving Childhood Cancer: A Guide for Families. Washington D.C.: American Psychiatric Press, 1998.

Ganz, Pam. Life Isn't Always A Day at the Beach: A Book for All Children Whose Lives Are Affected by Cancer. Lincoln, Nebraska: High-Five Publishing, 1996.

Pizzo and Poplack, eds. Principles and Practice of Pediatric Oncology. Baltimore, MD: Lippincott-Raven Publishers, 1997.

PERIODICALS

Lafferty, A. R. "Pituitary Tumors in Children and Adolescents."Journal of Clinical Endocrinology and Metabolism 84 (December 1999):4317-4322.

ORGANIZATIONS

American Cancer Society, 1599 Clifton Road, NE, Atlanta, GA30329-4251. (800)586-4872 <http://www.cancer.org>

National Cancer Institute, 9000 Rockville Pike, Bethesda, Maryland, 20892. (800)422-6237. <http:..www.nci.nih.gov>

The Wellness Community, 10921 Reed Harman Highway, Cincinnati, Ohio, 45242 (888)793-9355.

Childhood Brain Tumor Foundation, 20312 Watkins Meadow Drive, Germantown, MD 20867. (301)515-2900. <http://www.childhoodbraintumor.org>

Candlelighter Childhood Cancer Foundation, 3910 Warner St., Kensington, MD 20895. 1-800-366-2223.<http://www.candlelighters.org>

National Children's Cancer Society, Suite 600, 1015 Locust St. St. Louis, MO 63101. 1-800-532-6459. <http://www.children-cancer.com>

Wendy Wippel, M.Sc.

KEY TERMS

Congenital

—Existing at birth.

Cystic tumor

—A tumor that consists of a sac filled with fluid.

Solid tumor

—A tumor that consists of tissue.

Neuroendocrine

—Relating to nerves and glands that produce hormones.

Stereotactic surgery

—Surgery that used sophisticated methods of imaging internal organs in order to make the most precise surgical incisions.

Monoclonal antibodies

—Antibodies produced in bulk that act against a single target.

Liposomes

—An artificially produced, microscopic sphere, consisting of a drug surrounded by cell membrane, used to help drugs get into target cells.

QUESTIONS TO ASK THE DOCTOR

• Can you explain what kind of cancer I have?
• Can you show me where my tumor is located?
• How was this cancer diagnosed?
• What is my prognosis? What limitations will I have?
• What treatments are we going to pursue? What goals will these treatments have? What happens if these don't work?
• Are there any alternatives to these treatments?
• Do you have experience in treating this type of cancer?
• Is there anything I can do to optimize treatment? Are there any particular side effects I should expect?
• Are there complementary therapies that you would recommend?

Pituitary tumors

Definition

Pituitary tumors are abnormal growths in the pituitary gland.

Description

Located in the brain, the pituitary gland is often referred to as the "master gland" of the body. This is because it makes and releases (secretes) at least nine distinct hormones (including oxytocin, antidiuretic hormone [ADH], prolactin, thyroid-stimulating hormone [TSH], adrenocorticotropic hormone [ACTH], follicle-stimulating hormone [FSH], luteinizing hormone [LH], and human growth hormone [HGH]) that regulate the activities of several other endocrine glands and influence a number of physiological processes including growth, sexual development and functioning, and the fluid balance of the body. The pituitary is divided into two parts: front (anterior) and rear (posterior). Each half of the pituitary gland secretes specific hormones. Tumors in the anterior part are common and are usually noncancerous (benign). Tumors rarely develop in the posterior portion. Between 10% and 15% of all tumors in the skull are pituitary tumors, which makes them the third most common type of brain tumor.

Virtually all pituitary tumors arise from a single cell which, for unknown reasons, has grown out of control. Tumors that have originated from a single cell are called monoclonal. Some tumors secrete hormones normally made by the pituitary gland. Because the tumor cells are uncontrolled, they secrete large amounts of hormones. As a result, hormone imbalance occurs. The symptoms caused by the hormone imbalance are often the first sign of a pituitary tumor.

There are several different types of pituitary tumors. Pituitary adenomas (adenomas are tumors that grow from gland tissues) are the most common type. Most pituitary adenomas are benign, although they may spread to nearby tissues. Pituitary adenomas can be further classified based on which, if any, hormones are secreted by the tumor. Thirty-five percent of pituitary adenomas do not secrete hormones, 27% secrete prolactin (prolactinomas), and 21% secrete growth hormone. The remaining pituitary adenomas secrete sex hormones (6%), thyroid hormones (1%), or adrenal (adrenocorticotropic) hormones (8%). Plurihormonal adenomas secrete more than one type of hormone. Tumors that secrete adrenocorticotropic hormone cause Cushing's syndrome and Nelson's syndrome.

Craniopharyngiomas are benign tumors that originate in tissues next to the pituitary gland. Technically speaking, they are not pituitary tumors although they affect the pituitary gland. They are extremely difficult to remove and radiation does not stop craniopharyngiomas from spreading throughout the pituitary gland. Craniopharyngiomas account for less than 5% of all brain tumors.

Pituitary carcinoma is a very rare condition. Fewer than 100 cases have ever been reported. It is usually diagnosed when a pituitary tumor, which was believed to be an adenoma , spreads (metastasizes) to distant organs. These pituitary tumors may or may not release hormones. Because pituitary carcinoma is often diagnosed late, it has a high death rate.

Demographics

Pituitary tumors occur more frequently in women than in men. They usually develop between the ages of 30 and 40. Half of all craniopharyngiomas occur in children, with symptoms most often appearing between the ages of five and ten.

Causes and symptoms

The cause of pituitary tumors is not known. Most pituitary tumors presumably result from changes to the DNA of one cell, leading to uncontrolled cell growth. The genetic defects, multiple endocrine neoplasia syndrome type I (MEN I or Wermer's syndrome), McCune-Albright syndrome, and the Carney complex, are associated with pituitary tumors. However, these defects account for only a small percentage of the cases of pituitary tumors. Also, a pituitary tumor may result from the spread (metastasis ) of cancer from another site. Breast cancer in women and lung cancer in men are the most common cancers to spread to the pituitary gland. Other cancers that spread to the pituitary gland include kidney cancer, prostate cancer , melanoma , and gastrointestinal cancers .

Symptoms related to tumor location, size, and pressure on neighboring structures include:

• persistent headache on one or both sides, or in the center of the forehead
• blurred or double vision; loss of side (peripheral) vision
• drooping eyelid (ptosis) caused by pressure on nerves leading to the eye
• numb feeling on the face
• dementia
• drowsiness
• enlarged head
• eating excessive (hyperphagia) or abnormally small (hypophagia) amounts of food
• seizures

The specific symptoms associated with hormone-secreting tumors will vary depending on which hormones are being over-produced. Symptoms related to hormonal imbalance include:

• excessive sweating
• loss of appetite
• loss of interest in sex
• inability to tolerate cold temperatures
• nausea
• menstrual problems
• excessive thirst
• frequent urination
• dry skin
• constipation
• premature or delayed puberty
• delayed growth in children
• milk secretion in the absence of pregnancy or breast feeding (galactorrhea)
• reduced strength
• mood alterations (depression , anxiety, unstable emotions)
• muscle pain
• low blood sugar (sudden occurrence of shakiness and sweating)

Patients who have sudden pituitary failure caused by bleeding or tissue death (pituitary apoplexy also known as Sheehan's syndrome) may experience very severe headaches, confusion, loss of sight, and drowsiness. This condition is considered an emergency.

Tumors that secrete growth hormone cause a condition called acromegaly. This long-term condition is characterized by enlargement of the nose, ears, jaws, toes, and fingers. Joint pain, blood sugar imbalances, highblood pressure, carpal tunnel syndrome, and airway blockages can result.

Diagnosis

As many as 40% of all pituitary tumors do not release excessive quantities of hormones into the blood. Known as clinically nonfunctioning, these tumors are difficult to distinguish from tumors that produce similar symptoms. They may grow to be quite large before they are diagnosed.

The diagnosis of pituitary tumors is based on:

• the patient's own observations and medical history
• physical examination
• laboratory studies of the patient's blood and brain/spinal fluid (cerebrospinal fluid)
• x rays of the skull and other studies that provide images of the inside of the brain (CT, MRI)
• vision tests
• urinalysis

Treatment team

The treatment team for pituitary tumors may include a neuroendocrinologist, endocrinologist, neurosurgeon, oncologist, radiation oncologist, nurse oncologist, psychiatrist, psychological counselor, and social worker.

Clinical staging, treatments, and prognosis

Clinical staging

Because most pituitary tumors are benign, there is no clinical staging system.

Treatments

Treatment is determined by the type of tumor, the type of hormone being released, and whether or not the tumor has invaded tissues next to the pituitary gland. The goals of treatment are to normalize hormone levels and reduce the size of (or remove) the tumor. Treatment options include surgery, radiation, and/or medication. Some pituitary tumors stabilize without treatment. Small tumors that are not causing significant symptoms may be watched only.

Surgery is usually used to remove all or part of a tumor within the gland or the area surrounding it. Surgery may be combined with radiation therapy to treat tumors that extend beyond the pituitary gland. A neurosurgeon will operate immediately to remove the tumor or pituitary gland (hypophysectomy) of a patient whose vision is deteriorating rapidly. Approximately 96% of the surgeries are performed through the nose (transsphenoidal). If the tumor is large, the skull may be opened (craniotomy ) for tumor removal. Removal or destruction of the pituitary gland requires life-long hormone replacement therapy. The most common complications of surgery are leakage of cerebrospinal fluid through the nose and inflammation of the membranes that surround the brain and spinal column (meningitis).

Radiation therapy is not as effective as surgery and is usually reserved for tumors that have not responded to other treatments and those that recur. Radioactive pellets can be implanted in the brain to treat the tumor. Selected patients are treated with proton beam radiosurgery that uses high energy particles in the form of a high energy beam to destroy an overactive pituitary gland. Fatigue , upset stomach, diarrhea , and nausea are common complaints of patients having radiation therapy. Radiation therapy to the brain can damage certain brain tissues.

Dopamine agonists, drugs that increase the effect of the brain chemical dopamine, are effective in treating tumors that release hormones. These drugs can reduce symptoms caused by a pituitary tumor and reduce the size of the tumor. Commonly used dopamine agonists include bromocriptine, pergolide, and cabergoline. Cabergoline is the most effective and produces fewer side effects than the other two drugs. Side effects associated with dopamine agonists include nausea and vomiting , and light-headedness when rising (postural hypotension). Acromegaly may be treated with somatostatin and other drugs derived from somatostatin (analogues). Tumors, and the symptoms they are causing, return when drug use is stopped. Patients should wear medical identification tags identifying their condition and the hormonal replacement medicines they take.

The common treatments for specific pituitary tumors are:

• Prolactin-secreting adenoma. Prolactinomas are treated with a dopamine agonist. Surgical treatment is used if the drug fails or causes intolerable side effects.
• Gonadotropin-secreting adenoma. Small tumors are not treated unless they are causing symptoms. Large tumors and small tumors that are causing symptoms are treated surgically. Radiation therapy may be used.
• Adrenocorticotropic hormone-secreting adenoma. Surgery is the treatment of choice. Medications that prevent adrenal hormone production or radiation therapy may be used if surgery fails.
• Growth hormone-secreting adenoma. Surgery is the treatment of choice. Medications (dopamine agonists, somatostatins) or radiation therapy may be used.
• Thyroid stimulating hormone-secreting adenoma. Surgery, with or without radiation therapy, is the treatment of choice. Although somatostatin treatment may reduce hormone levels, it fails to shrink the tumor.
• Nonsecreting adenoma. Surgery is the treatment of choice. In general, medications are not effective for this type of tumor. Radiation therapy may be used to prevent tumor recurrence.
• Pituitary carcinoma. Carcinoma is treated with standard cancer radiation therapy and chemotherapy.
• Craniopharyngiomas. These tumors are difficult to treat. Due to the nature of craniopharyngiomas, surgery is often incomplete and needs to be complemented by radiation therapy.

Prognosis

Pituitary tumors are usually curable. Pituitary adenomas that secrete adrenocorticotropic hormone are frequently persistent and have a high rate of recurrence. Approximately 5% of pituitary adenomas invade nearby tissues and grow to large sizes, making them more difficult to treat and subject to frequent recurrences. Metastasis of most pituitary tumors is very rare. However, pituitary carcinomas can metastasize and are associated with a poor prognosis.

Alternative and complementary therapies

Alternative and complementary therapies have not been shown to be effective in treating pituitary tumors. For more comprehensive information, the patient should consult the book on complementary and alternative medicine published by the American Cancer Society listed in the Resources section.

Coping with cancer treatment

The patient should consult his or her treatment team regarding any side effects or complications of treatment. Patients may want to consult a psychotherapist and/or join a support group to deal with the emotional consequences of cancer and its treatment.

Clinical trials

As of early 2001, there are two active clinical trials studying pituitary tumors. Both trials are studying the safety and effectiveness of antineoplastons. Study #BRIBT-9 is open to patients with serious or life-threatening brain tumors. Study #BRI-NE-2 is open to patients who have metastatic or incurable neuroendocrine tumors . The National Cancer Institute web site has information on these and other studies. Patients should consult with their treatment team to determine if they are candidates for these or any other ongoing studies.

Special concerns

Long-term low levels of sex hormones (hypogonadism) can have negative effects on bone density and the cardiovascular system. The effect a pituitary tumor has on fertility is a concern for both men and women. Women taking medications to treat pituitary tumors need to question their physicians regarding the potential effect the medications may have on an unborn baby.

See Also Mutliple endocrine neoplasia syndromes

Resources

BOOKS

American Cancer Society's Guide to Complementary and Alternative Cancer Methods, edited by Katherine Bruss, Christina Salter, and Esmeralda Galan. Atlanta, GA: American Cancer Society, 2000.

DeAngelis, Lisa, and Jerome Posner. "Cancer of the Central Nervous System and Pituitary Gland." In Clinical Oncolo gy, edited by Raymond Lenhard, Robert Osteen, and Ted Gansler. Atlanta, GA: American Cancer Society, 2001, pp.653-703.

Endocrinology and Metabolism Clinics of North America: Advances in Pituitary Tumor Therapy, edited by Mark Molitch. Philadelphia: W.B. Saunders Company, 1999.

Pituitary Disorders: Comprehensive Management, edited by Ali Krisht, and George Tindall. Baltimore: Lippincott Williams & Wilkins, 1999.

PERIODICALS

Freda, Pamela, and Sharon Wardlaw. "Diagnosis and Treatment of Pituitary Tumors." The Journal of Clinical Endocrinol ogy & Metabolism 84 (November 1999): 3859-66.

ORGANIZATIONS

American Brain Tumor Association. 2770 River Road, Des Plaines, IL 60018. (800) 886-2289. <http://www.abta.org>.

American Cancer Society. 1599 Clifton Road NE, Atlanta, GA 30329. (800) ACS-2345. <http://www.cancer.org>.

Brain Tumor Information Services. Box 405, Room J341, Uni versity of Chicago Hospitals, 5841 S. Maryland Avenue, Chicago, IL 60637. (312) 684-1400.

Cancer Research Institute, National Headquarters. 681 Fifth Ave., New York, NY 10022. (800) 992-2623. <http://www.cancerresearch.org>.

National Institutes of Health. National Cancer Institute. 9000 Rockville Pike, Bethesda, MD 20982. Cancer Information Service: (800) 4-CANCER. <http://cancernet.nci.nih.gov>.

Maureen Haggerty

Belinda Rowland, Ph.D.

KEY TERMS

Adenoma

—A tumor that is derived from glandular tissue.

Agonist

—A drug that increases the effectiveness of another drug or chemical.

Benign

—A term used to describe a noncancerous growth.

Carney complex

—A genetic disorder characterized by myxomas, spotty pigmentation of the skin and mucous membranes, and endocrine overactivity.

Dopamine

—A neurotransmitter that is a chemical messenger in the brain.

Hormone

—A chemical that is produced and released by one organ to regulate the function of another organ.

Invasive

—A descriptive term for tumors that spread to nearby structures.

McCune-Albright syndrome

—A genetic disorder that includes bone, endocrine, and skin abnormalities. Some individuals with this syndrome show the effects of excessive secretion of pituitary growth hormone.

Multiple endocrine neoplasia syndrome type I

—An inherited disorder that affects the endocrine glands. The pituitary gland becomes overactive in about one-sixth of the individuals with this syndrome.

Nelson's syndrome

—An endocrine disorder characterized by increase secretion of ACTH and melanocyte stimulating hormone by the pituitary gland.

QUESTIONS TO ASK THE DOCTOR

• Is my tumor cancerous? Is it invasive?
• What are my treatment options?
• What are the risks and side effects of these treatments?
• Is surgery really necessary?
• Which surgical approach will you use?
• How experienced are you at performing pituitary surgery?
• How will I feel immediately following surgery?
• Will I need to take medication for the rest of my life?
• How long will it take for my symptoms to go away?
• Will I be able to have children?
• Is it safe to become pregnant while taking this medication?
• How will pregnancy affect my tumor?
• What medications can I take to relieve treatment side effects?
• Are there any clinical studies underway that would be appropriate for me?
• What is the chance that the tumor will recur?
• How will recurrence be detected?
• How often will I have follow-up examinations?

Pituitary Tumors

Definition

Pituitary tumors are abnormal growths on the pituitary gland. Some tumors secrete hormones normally made by the pituitary gland.

Description

Located in the center of the brain, the pituitary gland manufactures and secretes hormones that regulate growth, sexual development and functioning, and the fluid balance of the body. About 10% of all cancers in the skull are pituitary tumors. Pituitary adenomas (adenomas are tumors that grow from gland tissues) and pituitary tumors in children and adolescencents (craniopharyngiomas) are the most common types of pituitary tumors. They are usually benign and grow slowly. Even malignant pituitary tumors rarely spread to other parts of the body.

Pituitary adenomas do not secrete hormones but are likely to be larger and more invasive than tumors that do. Craniopharyngiomas are benign tumors that are extremely difficult to remove. Radiation does not stop them from spreading throughout the pituitary gland. Craniopharyngiomas account for less than 5% of all brain tumors. Pituitary tumors usually develop between the ages of 30 and 40, but half of all craniopharyngiomas occur in children, with symptoms most often appearing between the ages of five and ten.

Causes and symptoms

The cause of pituitary tumors is not known, but may be genetic. Symptoms related to tumor location, size, and pressure on neighboring structures include:

• persistent headache on one or both sides, or in the center of the forehead
• blurred or double vision; loss of peripheral vision
• drooping eyelid caused by pressure on nerves leading to the eye
• seizures

Symptoms related to hormonal imbalance include:

• excessive sweating
• loss of appetite
• loss of interest in sex
• inability to tolerate cold temperatures
• nausea
• high levels of sodium in the blood
• menstrual problems
• excessive thirst
• frequent urination
• dry skin
• constipation
• premature or delayed puberty
• delayed growth in children
• galactorrea (milk secretion in the absence of pregnancy or breast feeding)
• low blood pressure
• low blood sugar

Diagnosis

As many as 40% of all pituitary tumors do not release excessive quantities of hormones into the blood. Known as clinically nonfunctioning, these tumors are difficult to distinguish from tumors that produce similar symptoms. They may grow to be quite large before they are diagnosed.

Endocrinologists and neuroendocrinologists base the diagnosis of pituitary tumors on:

• the patient's own observations and medical history
• physical examination
• laboratory studies of the patient's blood and cerebrospinal fluid

• x rays of the skull and other studies that provide images of the inside of the brain (CT, MRI)
• vision tests
• urinalysis

Treatment

Some pituitary tumors stabilize without treatment, but a neurosurgeon will operate at once to remove the tumor (adenectomy) or pituitary gland (hypophysectomy ) of a patient whose vision is deteriorating rapidly. Patients who have pituitary apoplexy may experience very severe headaches, have symptoms of stiff neck, and sensitivity to light. This condition is considered an emergency. Magnetic resonance imaging (MRI) is the best imaging technique for patients with these symptoms. If the tumor is small, surgery may be done through the nose. If the tumor is large, it may require opening the skull for tumor removal. Selected patients do well with proton beam radiosurgery (the use of high energy particles in the form of a high energy beam to destroy an overactive gland).

Treatment is determined by the type of tumor and by whether it has invaded tissues adjacent to the pituitary gland. Hormone-secreting tumors can be successfully treated with surgery, radiation, bromocriptine (Parlodel), Sandostatin (Octreotide), or other somatostatin analogues (drugs similar to somatostatin). Surgery is usually used to remove all or part of a tumor within the gland or the area surrounding it, and may be combined with radiation therapy to treat tumors that extend beyond the pituitary gland. Removal of the pituitary gland requires life-long hormone replacement therapy.

Radiation therapy can provide long-term control of the disease if it recurs after surgery, and radioactive pellets can be implanted in the brain to treat craniopharyngiomas. CV205-502, a new dopamine agonist (a drug that increases the effect of another, in this instance dopamine) can control symptoms of patients who do not respond to bromocriptine.

Prognosis

Pituitary tumors are usually curable. Following surgery, adults may gradually resume their normal activities, and children may return to school when the effects of the operation have diminished, and appetite and sense of well-being have returned. Patients should wear medical identification tags identifying their condition and the hormonal replacement medicines they take.

Resources

ORGANIZATIONS

American Brain Tumor Association. 2770 River Road, Des Plaines, IL 60018. (800) 886-2289. 〈http://www.abta.org〉.

Brain Tumor Information Services. Box 405, Room J341, University of Chicago Hospitals, 5841 S. Maryland Ave., Chicago, IL 60637. (312) 684-1400.

KEY TERMS

Agonist— A drug that increases the effectiveness of another drug.

Analogue— A drug that is similar to the drug from which it is derived.

craniopharyngioma (kray-ni-oh-fă-rinj-i-oh-mă) n. a brain tumour derived from remnants of Rathke's pouch, the earliest detectable embryonic precursor of the pituitary gland.