Differential Diagnosis for Empty Sella on MRI
Single Most Likely Diagnosis
- Primary Empty Sella Syndrome: This condition is characterized by the herniation of the subarachnoid space into the sella turcica, often due to a defect in the diaphragma sellae. It is usually asymptomatic and discovered incidentally on imaging. The primary empty sella syndrome is the most common cause of an empty sella and is often associated with normal pituitary function.
Other Likely Diagnoses
- Secondary Empty Sella Syndrome: This occurs as a result of surgery, radiation, or infarction of a pituitary tumor, leading to the shrinkage of the pituitary gland and the appearance of an empty sella on MRI. Patients may have symptoms related to the underlying cause or hormonal deficiencies.
- Idiopathic Intracranial Hypertension: Although less common, idiopathic intracranial hypertension (IIH) can be associated with an empty sella. The increased intracranial pressure may cause the sella to appear empty due to the herniation of the subarachnoid space.
Do Not Miss Diagnoses
- Pituitary Apoplexy: Although it might not be the first consideration for an empty sella, pituitary apoplexy (hemorrhage or infarction of the pituitary gland) can sometimes present with an empty sella appearance on MRI, especially if there has been significant necrosis and shrinkage of the gland. This condition is a medical emergency due to the potential for acute hormonal deficiencies and visual disturbances.
- Lymphocytic Hypophysitis: An inflammatory condition of the pituitary gland that can cause it to shrink, potentially leading to an empty sella appearance. It is particularly important in pregnant women or postpartum, where it can lead to significant hormonal imbalances.
Rare Diagnoses
- Sella Turcica Bone Lesions: Rarely, lesions such as osteoporosis, Paget's disease, or other bone disorders affecting the sella turcica can give the appearance of an empty sella on MRI.
- Infectious or Inflammatory Conditions: Certain infections (e.g., tuberculosis, fungal infections) or inflammatory conditions (e.g., sarcoidosis, histiocytosis) can affect the pituitary gland and sella turcica, leading to an empty sella appearance. These conditions are rare but important to consider, especially in immunocompromised patients.
- Metastatic Disease: Metastases to the pituitary gland or sella turcica can cause destruction and shrinkage of the gland, resulting in an empty sella. This is a rare occurrence but should be considered in patients with a known history of cancer.