Taylor H C, Mayes D, Anton A H
J Clin Endocrinol Metab. 1986 Jul;63(1):238-42. doi: 10.1210/jcem-63-1-238.
Baseline plasma norepinephrine (NE) and epinephrine (E) levels over 2000 pg/ml or failure to suppress to less than 500 pg/ml after oral clonidine have been considered diagnostic of the presence of a pheochromocytoma. We found a false negative clonidine suppression test in a patient with an asymptomatic ACTH-secreting pheochromocytoma who had minimally increased resting plasma NE and E values of 669 and 419 pg/ml, respectively. Clonidine suppression caused decreases at 2 and 3 h to 372 and 408 pg/ml, respectively. A positive test was found in a patient with repeatedly elevated baseline plasma NE and E concentrations; the two highest results were 2501 and 3022 pg/ml. Clonidine administration on five occasions failed to decrease plasma NE and E levels to less than 500 pg/ml. However, no pheochromocytoma was found by selective venous catheterization, two laparotomies, and, ultimately, postmortem examination. Diffuse infiltration of lymphoplasmacytic cells throughout sympathetic ganglia and adrenal medulla raise the possibility of a diffuse autoimmune disorder, resulting in excessive catecholamine production. These examples suggest that the clonidine suppression test does not always indicate the presence or absence of a pheochromocytoma.
基线血浆去甲肾上腺素(NE)和肾上腺素(E)水平超过2000 pg/ml,或口服可乐定后未能抑制至低于500 pg/ml,被认为可诊断嗜铬细胞瘤的存在。我们在一名无症状促肾上腺皮质激素分泌性嗜铬细胞瘤患者中发现了可乐定抑制试验假阴性,该患者静息血浆NE和E值仅轻度升高,分别为669和419 pg/ml。可乐定抑制导致2小时和3小时时分别降至372和408 pg/ml。在一名基线血浆NE和E浓度反复升高的患者中发现了阳性试验结果;两次最高结果分别为2501和3022 pg/ml。五次给予可乐定均未能使血浆NE和E水平降至低于500 pg/ml。然而,通过选择性静脉插管、两次剖腹探查以及最终的尸检均未发现嗜铬细胞瘤。交感神经节和肾上腺髓质中淋巴细胞和浆细胞的弥漫性浸润增加了弥漫性自身免疫性疾病的可能性,导致儿茶酚胺产生过多。这些例子表明,可乐定抑制试验并不总是能表明嗜铬细胞瘤的存在与否。