| Type | Causes | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Tumors | Most cases of hypopituitarism are due to pituitary adenomas compressing the normal tissue in the gland, and rarely other brain tumors outside the gland—craniopharyngioma, meningioma, chordoma, ependymoma, glioma or metastasis from cancer elsewhere in the body. | ||||||||||||||||||
| Infection, inflammation and infiltration |
The pituitary may also be affected by infections of the brain (brain abscess, meningitis, encephalitis) or of the gland itself, or it may be infiltrated by abnormal cells (neurosarcoidosis, histiocytosis) or excessive iron (hemochromatosis). Empty sella syndrome is unexplained disappearance of pituitary tissue, probably due to outside pressure. Autoimmune or lymphocytic hypophysitis occurs when the immune system directly attacks the pituitary. | ||||||||||||||||||
| Vascular | As a pregnancy comes to term, a pregnant woman's pituitary gland is vulnerable to low blood pressure, such as may result form hemorrhage; pituitary damage due to bleeding after childbirth is called Sheehan's syndrome. Pituitary apoplexy is hemorrhage or infarction (loss of blood supply) of the pituitary. Other forms of stroke are increasingly recognized as a cause for hypopituitarism. | ||||||||||||||||||
| Radiation | Radiation-induced hypopituitarism mainly affects growth hormone and gonadal hormones. In contrast, adrenocorticotrophic hormone (ACTH) and thyroid stimulating hormone (TSH) deficiencies are the least common among people with radiation-induced hypopituitarism. Changes in prolactin-secretion is usually mild, and vasopressin deficiency apppears to be very rare as a consequence of radiation. | ||||||||||||||||||
| Other physical | External physical causes for hypopituitarism include traumatic brain injury, subarachnoid hemorrhage, neurosurgery and ionizing radiation (e.g. radiation therapy for a previous brain tumor). | ||||||||||||||||||
| Congenital | Congenital hypopituitarism (present at birth) may be the result of complications around delivery, or may be the result of insufficient development (hypoplasia) of the gland, sometimes in the context of specific genetic abnormalities. Mutations may cause either insufficient development of the gland or decreased function. Forms of combined pituitary hormone deficiency ("CPHD") include:
Kallmann syndrome causes deficiency of the gonadotropins only. Bardet-Biedl syndrome and Prader-Willi syndrome have been associated with pituitary hormone deficiencies. |
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