Pituitary apoplexy within a macroprolactinoma.

BACKGROUND: A 61-year-old lady was admitted to hospital with sepsis due to a urinary tract infection. Three days after admission, she suddenly started to have severe headache with visual disturbance and right third nerve palsy. Urgent magnetic resonance angiography excluded internal carotid artery aneurysm but showed a large lesion extending superiorly from the clivus towards the right cerebral peduncle, which was confirmed by a CT scan of the brain. The lesion was initially thought to be a primary or a metastatic brain tumor. CT scans of the thorax, abdomen and pelvis showed no evidence of metastatic disease. MRI scan revealed a huge pituitary adenoma containing hemorrhage. Subsequent pituitary function tests indicated a grossly elevated serum prolactin level and hypopituitarism. INVESTIGATIONS: Magnetic resonance angiography of the head; CT scans of the brain, thorax, abdomen and pelvis; MRI scan of the pituitary gland; and baseline and dynamic anterior pituitary function testing. DIAGNOSIS: Pituitary apoplexy within a macroprolactinoma. MANAGEMENT: Steroid replacement, careful control of fluid and electrolyte balance and conservative nonsurgical management with the dopamine agonist cabergoline resulted in resolution of the patient's headache, improvement of the third nerve palsy and subsequent normalization of the prolactin level, with reduction in size of the prolactinoma on MRI scan.