MEDICAL SURFARI: PITUITARY -- THE PENTIUM OF THE BRAIN

The pituitary gland is about the size of a garbanzo bean and sits in a depression in the base of the skull called the sella turcica (Turkish saddle). Its name is derived from Latin as in ancient times it was thought to be the source of the glutinous mucus emanating from the nose.

This small ductless gland rests in the middle of the skull base between the eyes and directly behind the bridge of the nose. It is one of three systems that emerge from the brain and spinal cord. Two of these are neural. One of these neural systems affects our organ systems and the other the remainder of our body. The third efferent system is humoral---the neuroendocrine system (hormones).

This little gland could be likened to the Pentium processor of current desktop computer systems. The pituitary gland is employed by the neuroendocrine system to regulate the function of many organs including the kidneys, uterus and breasts and it supports and regulates the function of other organs that secret hormones such as the thyroid and adrenal glands, ovaries and testicles. The pituitary gland affects the growth and development of our bodies as it maintains and regulates metabolism and it plays a vital role in reproduction.

Tomes have been written about the pituitary and its physiology. Perhaps even more has been written about the conditions produced by disorders of the pituitary.

Space simply does not permit even a summary discussion of the conditions that may arise from abnormal pituitary function. I will limit this column to pituitary tumors that usually arise from the pituitary gland. Most pituitary tumors are benign (non-cancerous), generally grow very slowly and do not spread to other parts of the body.

They usually become apparent either due to a hormonal disturbance or due to the pressure they produce upon other parts of the nervous system, namely the optic nerves. If the optic nerves become compressed by a pituitary tumor this may cause poor or absent peripheral vision. Pituitary tumors may be the cause of menstrual disorders, decreased libido (interest or desire in sex), headache, vision impairment, growth failure, fatigue and even excessive thirst and frequent urination.

Certain types of tumors may cause infertility, osteoporosis, gigantism, dwarfism, impotence, marked changes in ring or shoe size, enlargement of the hands, feet, facial features or tongue.

Other tumors may cause fat buildup in the face, back and chest resulting in weight gain while the arms and legs become relatively thin. Some patients with pituitary tumors develop mood swings or excessive hair growth, severe stretch marks and even irregular or rapid heart rate. If your doctor suspects a pituitary tumor, blood tests are necessary to determine how the tumor has affected the neuroendocrine system. Usually a MRI of the brain is done to judge the size and characteristics of the tumor.

Treatments for pituitary tumors depend upon the type and size of the tumor as well as the patient's age and overall health. Generally, these tumors are treated by medication, radiation therapy or surgery. Many tumors can be treated with medications alone but some require one or more of the other types of treatment. Remember, tumors of the pituitary gland are almost invariably benign and are usually curable.

Worldwide Web Resource

National Cancer Institute: Pituitary Tumor

www.icic.nci.nih.gov/clinpdq/pif/Pituitary_tumor_Patient.html

This web site describes types of pituitary tumors as well as treatment options for patients. A related web page provides information for health professionals treating pituitary problems.

Dr. Scott Gibbs is a Cape Girardeau neurosurgeon and editor-in-chief of Mosby's Medical Surfari. You may e-mail questions to him at drgibbs@semissourian.com or write in care of the Southeast Missourian, P.O. Box 699, Cape Girardeau, Mo., 63702-0699.