empty sella is usually an incidental finding seen in some patients on CT brain scan
it implies that the pituitary is either shrunken or displaced from the sella turcica by subarachnoid fluid due to raised intracranial pressure with herniation of the arachnoid space into pituitary fossa through a deficient diaphragm, found in 20% of the population
partial empty sella refers to a sella turcica filled less than 50% with CSF, and complete empty sella refers to a sella filled to more than 50% with CSF
aetiology
primary idiopathic empty sella
congenital incompetent diaphragm sellae is thought to be a potential pathophysiologic cause of primary empty sella
secondary empty sella
benign raised intracranial pressure hence incidence higher in females, obesity
pituitary infarction - Sheehan's syndrome
trauma / surgery / radiation / etc
DDx includes local cystic lesions
cystic pituitary macroadenoma
may produce hyperprolactinaemia and galactorrhoea
arachnoid cyst
Rathke's cleft cyst
craniopharyngioma
epidermoid cyst
clinical features
asymptomatic
may have headaches associated with benign raised intracranial hypertension if this is the cause
hypopituitarism
hyperprolactinaemia is present in 10% to 17% of cases resulting from a microprolactinoma or functional hyperprolactinemia 1)
growth hormone deficiency is identified in 4% to 60% of patients, but the clinical significance in adults is unclear 2)
consider screening with early morning fasting cortisol levels
gonadotropin deficiency is seen in 2% to 32% of patients
adrenocorticotropin, thyroid-stimulating hormone, and antidiuretic hormone deficiencies are seen in about 1% of individuals with empty sella