The anatomy of the pituitary fossa is complex. The wall of the fossa can vary, resulting in inconsistencies in the nature and integrity of the sella barrier. Cerebrospinal fluid is generally confined to the subarachnoid space and does not circulate freely in the pituitary fossa. Spontaneous haemorrhage in the fossa typically occurs in the context of pre-existing intrasellar pathology such as a pituitary adenoma. Extravasation of blood into the subarachnoid space can rarely be observed following pituitary apoplexy. We describe the unique occurrence of subarachnoid haemorrhage in a largely empty pituitary fossa after the rupture of a cerebral aneurysm.
Pituitary apoplexy and subarachnoid haemorrhage (SAH) are both high in the differential diagnosis of sudden onset severe headaches.
Haemorrhagic pituitary apoplexy may result in extravasation into the subarachnoid space, resulting in typical SAH symptoms and signs.
This is the first reported case of primary SAH resulting in blood pooling in an empty sella arising from previous surgical resection of a large macroadenoma.