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Information About Endocrine Cancers: Pituitary Tumors

The Stanford Pituitary Center provides comprehensive, streamlined care for patients with pituitary abnormalities, including pituitary tumors and pituitary hormone problems. View more information about the services available at Stanford.

What are pituitary tumors?

The pituitary gland is a small, pea-sized organ in the brain behind the back of the nose. The pituitary gland produces hormones that affect many other glands in the body. Although rare, most pituitary tumors are noncancerous (benign), comprising only 10 percent of brain tumors. However, because of the location of the pituitary gland, at the base of the skull, a pituitary tumor grows upward. And, eventually, many pituitary tumors press against the optic nerves, causing vision problems. What are symptoms of pituitary tumors?

What are symptoms of pituitary tumors?

Symptoms vary depending upon what type of tumor is growing and what area of the pituitary gland is affected. Pituitary tumors can cause symptoms that are caused by excess production of pituitary hormones and symptoms caused by reduced production of pituitary hormones. Other symptoms may be due to the proximity of these tumors to local brain structures, such as the optic nerves leading to loss of vision. Each individual also experiences symptoms differently, and the symptoms many resemble other conditions or medical problems. Always consult your physician for a diagnosis.

Causes and types of tumors:

Researchers do not know at this time what causes pituitary tumors. However, research studies show that having a hereditary condition, multiple endocrine neoplasia, type I (MEN 1), increases the risk of developing pituitary tumors, parathyroid tumors, and pancreatic tumors. Multiple endocrine neoplasia, type I (MEN 1) has been shown to be responsible for about all inherited (those that run in families) pituitary tumors, but only 3 percent of all pituitary tumors.

The most common type of pituitary tumor is called a clinically nonfunctioning tumor, because patients do not have the classic pituitary syndromes from excess hormones, such as in acromegaly.  These types of tumors may be detected during an evaluation of an incidental problem.  A clinically nonfunctioning tumor may cause hypopituitarism, or an underactive pituitary gland, which may lead to failure of sexual function, reduced sperm production, and cessation of a woman's menstrual period, along with fatigue.

Another common pituitary tumor is called a prolactinoma, a benign tumor that produces the prolactin hormone. Prolactin stimulates breast milk production after childbirth. Women with a prolactinoma may have reduced or absent menstrual cycles along with breast milk production. 

An uncommon pituitary tumor causes excess growth hormone production (a hormone necessary for normal childhood growth) resulting in acromegaly.  In adults, such tumors lead to excessive somatic growth and multiple systemic, medical consequences.  Another uncommon pituitary tumor results in Cushing’s disease, a disorder of excess steroid production.

According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), autopsy studies indicate that 25 percent of the US population have small pituitary tumors. Forty percent of these pituitary tumors produce prolactin, but most are not considered clinically significant. Clinically significant pituitary tumors affect the health of approximately 14 out of 100,000 people.

How are pituitary tumors diagnosed?

In addition to a complete medical history and medical examination, diagnostic procedures for pituitary tumors may include:

Treatments at Stanford

Patients can receive an evaluation and treatment for prolactinoma at the  Stanford Pituitary Center by calling: 

Treatment for pituitary tumors:

Specific treatment for pituitary tumors will be determined by your physician based on: Treatment may include:

Stanford Medicine Resources:

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