Apoplexy of a pituitary macroadenoma with reversible third, fourth and sixth cranial nerve palsies following administration of hypothalamic releasing hormones: MR features.

Pituitary apoplexy in patients with pituitary macroadenomas can occur either spontaneously or following various interventions. We present a case of a 71-year-old woman who developed third, fourth, and sixth cranial nerve palsies following administration of the four hypothalamic releasing hormones for routine preoperative testing of pituitary function. The MR examination showed interval tumor growth with impression of the floor of the third ventricle. There were also changes in signal intensity characteristics of the mass, suggestive of intratumoral bleeding. A transsphenoidal surgery with subtotal resection of the pituitary adenoma was performed. Microscopical examination revealed large areas of necrosis and blood surrounded by adenomatous tissue. Third, fourth, and sixth cranial nerve palsies completely resolved within 4 months. We conclude that MR imaging is useful in the demonstration of pituitary apoplexy following preoperative stimulation tests, but we suggest that these tests should be abandoned in patients with pituitary macroadenomas.