PITUITARY DISORDERS
The most frequent type of pituitary disorder is a pituitary gland tumor. These tumors are common in adults. They are not brain tumors and are almost always benign. There are two types of tumors—functioning and non-functioning. Functioning tumors produce too much of a hormone normally made by the pituitary, and non-functioning tumors do not. Both types of tumors can cause problems if they are large and interfere with normal function of the pituitary gland and/or nearby structures in the brain.
Symptoms of pituitary tumors vary depending on whether they are caused by the tumor mass or hormonal changes (either too much or too little hormone). The list of possible symptoms is long. Symptoms of tumor mass pressure can include headaches and trouble seeing, especially problems with peripheral vision. Symptoms of low pituitary hormones include fatigue, dizziness, dry skin, irregular periods in women, and sexual dysfunction in men. Other symptoms depend on the hormone that is affected.
ACTH-producing Tumors: Cushing Disease is a form of Cushing Syndrome. Cushing disease occurs when a benign tumor in the pituitary gland causes the pituitary gland to produce too much ACTH, the hormone responsible for cortisol production. Too much ACTH in the body causes the adrenal glands to produce cortisol in high levels.
Growth Hormone-producing Tumors: Acromegaly is usually caused by a non-cancerous tumor in the pituitary gland. The tumor produces too much GH and raises the level of GH in the blood. Too much GH also raises the level of insulin-like growth factor-1 (IGF-1), a hormone produced in the liver that also promotes growth.
Prolactin-Secreting Tumors: A prolactinoma is the most common secretory tumor, accounting for about 40% of pituitary tumors. This tumor produces too much prolactin, the hormone that causes milk production, also called hyperprolactinemia. Prolactinomas affect both men and women with now known cause. While milk leaking from breasts is one of the symptoms of a prolactinoma in women, and occasionally in men, there are many other signs of this kind of tumor.
