Infarction followed by hemorrhage in pituitary adenoma due to endocrine stimulation test

A 63-year-old man, who presented with visual field loss due to pituitary tu mor, received an intravenous bolus injection of thyrotropin and gonadotropi n releasing hormones and insulin as a preoperative evaluation. He complaine d of severe headache and nausea 2 hours after injection. Emergent CT scan s howed no evidence of intratumoral hemorrhage. The next day, his visual fiel d became null. MR images revealed heterogeneous mixed intensity lesions. Un der diagnosis of pituitary apoplexy, he underwent transsphenoidal tumor rem oval 30 hours after onset. Intraoperative and pathological findings showed tumor hemorrhage and adjacent necrotic change. Fourteen cases with sufficie nt clinical detail in the literature are reviewed: All of the cases had mac roadenoma with suprasellar extension. Testing agents were gonadotropin and thyrotropin releasing hormones in 92.9% and 85.7% of cases, respectively. H eadache was an initial symptom and started within two hours in all cases bu t one. Half of the cases showed no change on CT scan. However, tumor hemorr hage was evidenced in 92.9% of cases with or without necrosis due to ischem ic change, intraoperatively or pathologically. It is speculated that pituit ary apoplexy often starts with infarction possibly due to vasoactive effect of testing agents and later develops into hemorrhage. Therefore, it is nec essary to observe patients closely at least a few hours after endocrine sti mulation test, and MR imaging may make an earlier diagnosis for the pituita ry apoplexy since CT scan often shows no density change in the pituitary ad enoma.