What is an empty sella?
The term empty sella is actually a misnomer, for the sella is not empty, it is usually filled with cerebrospinal fluid. Empty sella is one of the more common incidental findings on MRI’s and CT scans of the head performed for other reasons. There are two main causes of an empty sella. First, there can be a congenital large opening in the tough membrane that is stretched over the top of the socket (sella) for the pituitary gland. This opening allows the transmission of spinal fluid pressure into the sella and consequent flattening of the pituitary gland. Second, patients can have inflammatory disorders (lymphocytic hypophysitis, sarcoidosis) or tumors that degenerate creating a void within the sella. The void is then filled with spinal fluid as the more flexible membranes surrounding the brain herniate into the sella. Patients with empty sella usually have normal pituitary function but some may have one or more pituitary hormone deficiencies. An occasional patient has a coexisting empty
