The pituitary gland is a small gland located at the base of the brain. It makes several hormones that control the function of other glands in the body, including the thyroid, the adrenal glands, and the 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 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 such as head trauma or an event such as surgery or radiation therapy, the condition is called secondary empty sella syndrome.

Primary empty sella syndrome is most often an incidental finding during 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% to 15 % of patients, and the elevated prolactin may interfere with normal function of the testes or ovaries.

Medications such as bromocriptine that suppress prolactin production are effective in correcting the problem.

Patients with an empty sella due syndrome 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.