Pituitary apoplexy after pituitary function test: a report of two cases and review of the literature

Abstract

BACKGROUND Although most of pituitary apoplexy occur spontaneous, some precipitating factors have been reported. We experienced two cases of pituitary apoplexy after a pituitary function test. METHODS In order to clarify the causal relation between the pituitary function test and apoplexy, we presented our two cases and reviewed 20 cases in the literature. RESULTS(Case 1) A 48-year-old man with a pituitary macroadenoma received an injection of 500μg thyrotropin-releasing hormone (TRH), 100μg gonadrotopin-releasing hormone (GnRH), and 0.1U/kg insulin as a preoperative test of pituitary function. Fifteen minutes later, he complained of diminished vision and headache. (Case 2) A 54-year-old man with a large cystic adenoma had an administration of 500μg TRH and 100μg GnRH. Ten minutes later, he complained of blurring of his left eye and headache. Although, in both cases, CT scans showed neither intratumoral hemorrhage nor infarction, the surgical specimen showed necrotic and hemorrhagic adenoma. The patients made excellent clinical recoveries after surgical decomposition Twenty-two reports including our two cases were reviewed in 15 cases (68%), TRH was associated with apoplexy events and seemed to be the agent most likely to have an etiologic role because of its vasoactive properties. Eighteen patients (82%) had pituitary macroadenoma with suprasellar extension. In 72% of 18 surgical cases, some recovery of visual function was obtained. CONCLUSIONS An apparent relationship between the test and the apoplexy events raises the possibility of the development of pituitary apoplexy after a pituitary function test. Unless there is a specific indication, pituitary function test should be avoided especially in patients with a large pituitary tumor.