Absence of the pituitary gland on radiological imaging of the sella turcica, a bony structure that partly surrounds the gland.
Causes, incidence, and risk factors
The pituitary gland is a small, oval gland at the base of the brain. It makes several hormones that control the function of other glands in the body including the thyroid gland, adrenal glands, and gonads (ovaries or testes). The pituitary gland is partly surrounded by a bony structure called the sella turcica (Turkish saddle). When the pituitary gland is not visible on CT or MRI scans of the sella turcica, the condition is referred to as the empty sella syndrome. Primary empty sella syndrome occurs when a small anatomical defect above the pituitary gland increases pressure in the sella turcica and causes the gland to flatten out along the walls of the sella. When the sella is empty because the pituitary gland has regressed following an injury (e.g., surgery, head trauma, radiation therapy), the condition is called secondary empty sella syndrome. Primary empty sella syndrome is most often an incidental finding on radiological imaging of the brain. Pituitary function is usually normal, and patients do not have any symptoms. The hormone prolactin is mildly elevated in 10-15 % of patients, and the elevated prolactin may interfere with normal function of the testes or ovaries. Medications that suppress prolactin production (e.g., bromocriptine) are effective in correcting the problem. Patients with an empty sella due to destruction of the pituitary gland have signs and symptoms caused by partial or complete loss of pituitary gland functions. The causes and symptoms of pituitary insufficiency are reviewed in the article on hypopituitarism. Empty sella syndrome is often associated with abnormal pituitary function in children. Isolated deficiency of growth hormone (GH) is most common, but other pituitary hormones may also be deficient. One study observed empty sella in 48% of children with GH deficiency or multiple pituitary hormone deficiencies compared to only 2% of children with normal pituitary function.
Signs and tests
Brain imaging studies:
Enlarged sella and absent pituitary gland on CT scan Enlarged sella and absent pituitary gland on MRI scan Tests of pituitary gland function may be performed to make sure that the gland is working normally. Pituitary gland testing is reviewed in the article on hypopituitarism.
Treatment
Primary empty sella syndrome:
No specific treatment if pituitary function is normal Medication to lower prolactin levels (e.g., bromocriptine) if the prolactin level is high and interfering with gonadal function Secondary empty sella syndrome: therapy is directed at replacing hormones that are deficient as a result of abnormal pituitary gland function. See the article on hypopituitarism for a complete review.
Calling your health care provider
Contact your health care provider is symptoms of abnormal pituitary function occur. These are reviewed in the article on hypopituitarism and include manifestations such as disrupted menstrual cycle or impotence.
Prevention
There is no way to prevent empty sella syndrome.