Pituitary apoplexy has been reported as a very rare complication of combined tests of anterior pituitary function and of TRH or
gonadotropin-releasing hormone (
GnRH) administration in
pituitary tumor. A 34-year-old man with a GH-secreting pituitary macroadenoma and
diabetes mellitus received an injection of 400 microg TRH, 100 microg
GnRH, and 0.15 U/Kg
regular insulin. Twenty minutes later, he complained of a severe
headache and vomited. Visual acuity and visual field did not change and his
headache was persistent during the next 24 hours of
conservative management. Magnetic resonance imaging (MRI) of the sella turcica done the day after the event showed definitive elevation of the optic chiasm and slight enlargement of
tumor and focal areas of mixed high signal and low signal intensities in the macroadenoma on noncontrast T1-weighted images.
Headache subsided markedly within a day of
octreotide therapy. Transsphenoidal removal of the
pituitary tumor was performed 9 days after the
hormone study. Ischemic
necrosis and
hemorrhage were confirmed in the
acidophilic adenoma with positive immunostaining for GH. Postoperative course was uneventful and his serum
insulin-like growth factor-1 (IGF-1) level and
blood glucose levels were normalized. Three months after the surgery the dynamic test was repeated without adverse effects. To our knowledge, this is a very rare case of
apoplexy of
GH-secreting pituitary adenoma after a combined stimulation test of anterior pituitary function.