Empty sella sign

The empty sella sign is a radiological finding characterized by the partial or complete filling of the sella turcica with cerebrospinal fluid (CSF), causing the pituitary gland to appear flattened or compressed against the walls of the sella. This results in the sella appearing "empty" on imaging, despite the presence of a compressed pituitary gland. The empty sella sign is typically identified on magnetic resonance imaging (MRI) or computed tomography (CT) and can be associated with various clinical conditions or incidental findings.

The empty sella sign occurs due to herniation of the subarachnoid space into the sella turcica, displacing the pituitary gland and allowing CSF to occupy the space. This phenomenon is often linked to the following mechanisms:

In both primary and secondary cases, the pituitary gland is often compressed but retains some degree of function.

MRI is the gold standard for diagnosing the empty sella sign. Key features include:

On CT, the empty sella sign may appear as hypodensity in the sella, corresponding to CSF. There may be possible sellar floor thinning or remodeling due to chronic pressure changes.