The pituitary gland is a tiny organ located at the base of the brain. It is considered the master gland of the body because it controls biochemical processes important to our well-being.  In addition to producing and secreting many hormones, it stimulates other glands to produce different types of hormones. The most frequent cause of pituitary disorders is pituitary gland tumors and they are fairly common in adults. They are not brain tumors, nor are they a form of cancer---cancerous pituitary tumors are extremely rare. Pituitary tumors can interfere with the normal formation and release of hormones.

Causes
Most pituitary tumors occur spontaneously and are not genetically inherited. Like many other tumors, the actual cause of pituitary tumors remains unknown.

Symptoms
The symptoms of pituitary tumors vary depending on the size, location and whether the tumor affects the secretion of hormones by overproduction or underproduction of hormones. Secretory tumors produce too much of a hormone, creating an imbalance of proper hormones in the body. Non-secretory tumors cause problems because of their large size or because they interfere with normal function of the pituitary gland. Large pituitary tumors — those measuring about 3/4 inch (19 millimeters) or larger can exert physical pressure on the rest of the pituitary gland and nearby structures such as the optic nerves, which are in close proximity to the pituitary gland. Some pituitary tumors, called functioning tumors, may themselves produce hormones. Different types of functioning tumors can cause specific signs and symptoms.Some patients with large tumors may have acute hemorrhage into the tumor, a condition known as "pituitary apoplexy" which causes sudden onset of headache, visual loss, double vision, and/or pituitary failure. This condition is a medical emergency and immediate decompressive surgery is critical.

Diagnosis
In addition to a complete medical history, physical examination and hormonal studies, Dr. Gallivan may order magnetic resonance imaging (MRI) to diagnose pituitary tumors. Other tests such as computed tomography (CT) may also be helpful. Visual studies are important for evaluating any possible or existing visual field defects caused by large tumors that compress the optic pathways.

Treatment
Pituitary tumors are treatable and in many cases curable. The optimal treatment depends on the type and size of the tumor, and how far it has grown into the surrounding brain at the time of diagnosis. Early detection of pituitary tumors is often "key" to successful treatment. The goal of treatment, and the best measure for its success, is to reduce pressure on nearby structures (generally the optic nerves or the pituitary gland itself) and/or to restore normal production levels of hormones.