Empty sella turcica

Empty sella turcica is the definition of a sellar cavity partially or completely filled with cerebrospinal fluid irrespective of its size. Widespread use of CT and MR scanning in head and neck disease and pituitary disorders has led to the frequent demonstration of empty sellae, usually enlarged and mostly filled by intrasellar herniation of the suprasellar cisternae at the expense of the pituitary parenchyma which is generally shrunken to various degrees. This particular appearance of the sellar cavity and its content is usually secondary to spontaneous involution (ischaemic necrosis, bleeding) or medical or surgical treatment for pituitary adenomas. More seldom it is caused by other sellar-parasellar disease or the result of a congenitally incomplete sellar diaphragm with or without impaired CSF dynamics. Empty sella may also be linked to previous known (secondary empty sella) or unrecognised (primary empty sella) sellar or extrasellar disease. Empty sella may be clinically asymptomatic or present with the clinical features of empty sella syndrome characterised by headache hormonal disorders and visual disturbances. Adult empty sella syndrome must be distinguished from a broader spectrum of symptoms and child empty sella syndrome mainly characterised mainly by hormonal disorders, usually partial or global hypopituitarism. Another sporadic finding in empty sella is spontaneous rhinorrhoea from sphenoid cerebrospinal fluid fistula. MR rather than CT offers all the details of empty sella from morphological and size changes of the cellar cavity, shrinkage of the pituitary parenchyma, stretching of the pituitary stalk which may or may not lie on the median line, deformation and possible intrasellar herniation of the suprasellar optic pathways and third ventricle. Nowadays, recourse to CT cisternography is only justified in cases of cerebrospinal fistula. Differential diagnosis does not usually raise problems when the typical features of empty sella are displayed; MR is the method of choice for follow-up scans.