Pituitary Disorders
Conditions
- Hypopituitarism: Hypopituitarism (pituitary insufficiency) is defined as failure of the gland to make one or more of the following anterior pituitary hormones: growth hormones (GH), prolactin (PRL), adrenocorticotropin (ACTH), thyrotropin (TSH), leuteinizing hormone (LH), or follicle stimulating hormone (FSH).
- Cushing’s Syndrome and Disease: Cushing’s syndrome can be seen to exist as a continuum. Cortisol is normally released in response to any stress, such as physical, psychological, infection or trauma stress. Since cortisol levels are usually not reduced until the stressor is removed, many people are suffering from a chronic form of low level Cushing’s syndrome that we can call hypercortisolism. Cushing’s disease implies a pituitary origin, typically due to excess ACTH release from a pituitary adenoma.
- Pituitary Tumors: Pituitary tumors that produce hormones are called functioning tumors. Tumors that don’t produce hormones are known as nonfunctioning pituitary tumors. The signs and symptoms of a functioning pituitary tumor result from excessive or insufficient hormone production, or from pressure of the tumor on surrounding tissues.
- Hyperprolactinemia: Hyperprolactinemia is a common disorder characterized by excess PRL production by the anterior pituitary. Functional hyperprolactinemia is often undiagnosed because serum PRL levels often appear within normal laboratory range. In addition, pituitary microadenomas may escape detection by standard imaging techniques.
Associated Syndromes and Etiologies
Pituitary tumors are common. In autopsy studies of patients who did not have known pituitary disease, as many as 26% had a small tumor (adenoma) in the gland.
The DNA mutations that cause tumors in people with multiple endocrine neoplasia type I (MEN1) have been identified. This condition is responsible for nearly all pituitary tumors that run in families, but only about 3% of all pituitary tumors. A mutation of the MEN1 gene has recently been identified as being responsible for a protein called menin. Although patients affected by the MEN1 syndrome can develop tumors of some glands as early as their teenage years, the pituitary tumors usually occur in adults.
