Empty Sella Syndrome

Definition and anatomical prerequisites

Empty sella syndrome is a rare pathology based on an anatomical defect. Normally, the pituitary gland is located in a bony depression (sella turcica) and separated from brain structures by a special membrane—the diaphragma sellae.

In this syndrome, there is a defect in this membrane or the formation of an excessively large opening for the pituitary stalk. Radiography reveals a specific sign that gave the disease its name: the pituitary gland does not fill the entire sella turcica as it normally does. Visually, the sella appears "empty".

Pathogenesis: how the pituitary gland is destroyed

The development of the disease represents a clear sequence of pathological changes:

1. Due to the diaphragmatic defect, cerebrospinal fluid penetrates into the cavity of the sella turcica.
2. Constant pressure of the cerebrospinal fluid on the pituitary tissue occurs.
3. Organ deformation and impaired transport of liberins (hypothalamic hormones) take place.
4. The final stage is the gradual atrophy and sclerosis of the gland.

General etiological factors contributing to the development of pituitary pathologies also include the influence of neurotransmitters (serotonin, endogenous opioids, histamine, oxytocin) and decreased renal and hepatic function.

Secondary development of the syndrome

Empty sella syndrome can develop secondarily against the background of other severe diseases leading to the destruction of pituitary tissue. These include:

• Sheehan's syndrome. It occurs due to necrosis of a part of the anterior pituitary gland caused by impaired blood supply during childbirth with profuse bleeding. The damage mechanism involves the appearance of abnormal proteins in the blood that cause an autoimmune lesion (facilitated by the absence of the blood-brain barrier in the pituitary).
• Pituitary cachexia (Simmonds' syndrome). It develops with massive necrosis of at least 90% of adenohypophysis cells (against the background of sepsis, trauma, or tumors). It is characterized by pronounced cachexia with a weight loss of 20–25 kg already in the first month.
• Pituitary adenoma infarction. The dead tumor tissue is eventually replaced by connective tissue.
• Iatrogenic causes. For example, the consequences of X-ray irradiation of the pituitary gland.

Clinical manifestations and hypopituitarism

Empty sella syndrome belongs to non-neoplastic forms of anterior pituitary lesions. The main consequence of glandular atrophy is the development of hypopituitarism (a condition characterized by decreased hormone synthesis).

The clinical picture consists of symptoms of trophic hormone deficiency:

• Decreased gonadotropin production leads to reproductive dysfunction. In particular, this is one of the causes of amenorrhea due to disorders at the adenohypophysis level.
• Growth hormone (GH), adrenocorticotropic hormone (ACTH), and thyroid-stimulating hormone (TSH) deficiency causes complex endocrine disorders.

In severe cases, especially when combined with necrosis syndromes, panhypopituitarism—a progressive decrease in the functions of all endocrine glands—may develop.

Differential diagnosis

When signs of hypopituitarism are detected, empty sella syndrome must be differentiated from other causes of adenohypophysis hypofunction. This list includes:

• Tumors (non-secreting chromophobe adenomas, oncocytomas).
• Suprasellar hypothalamic tumors (gliomas, craniopharyngiomas).
• Infectious lesions (tuberculosis, syphilis, toxoplasmosis, malaria).
• Granulomatoses (sarcoidosis, histiocytosis X) and autoimmune lymphocytic hypophysitis.
• Vascular pathologies (internal carotid artery aneurysms).

Class and exam questions

What else to study on this topic

• Sheehan's syndrome (postpartum pituitary necrosis)
• Pituitary cachexia (Simmonds' syndrome)
• Panhypopituitarism: clinical picture and consequences
• Neoplastic forms of pituitary lesions (adenomas, prolactinoma)
• Suprasellar hypothalamic tumors (craniopharyngioma)

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.