Morio H, Terano T, Yamamoto K, Tomizuka T, Oeda T, Saito Y, Tamura Y, Sasano H
Second Department of Internal Medicine, Chiba University, School of Medicine, Japan.
Endocr J. 1996 Aug;43(4):387-96. doi: 10.1507/endocrj.43.387.
The reported number of adrenal incidentalomas has been increasing because of wider application of imaging techniques. Patients with asymptomatic cortisol producing adrenal adenoma (ASCA) which secretes cortisol without clinical evidence of Cushing's syndrome has been more frequently observed than previously assumed, and they have a risk of adrenal insufficiency after adrenalectomy. Therefore patients with incidentalomas should be screened for cortisol overproduction. The aim of this study is to discover an easy screening test to uncover ASCA. We investigated the hormone profiles of 4 patients with ASCA in comparison with 11 patients with non-functional adrenal tumor and 10 patients with adrenal Cushing's syndrome. We also investigated the expression of dehydroepiandrosterone sulfotransferase (DHEA-ST) in surgically removed attached non-neoplastic adrenal tissues by immunostaining, which was considered to represent the degree of suppression of the hypothalamo-pituitary-adrenal axis. Serum dehydroepiandrosterone sulfate (DHEA-S) levels of all the patients with ASCA and adrenal Cushing's syndrome were lower than those of healthy subjects of corresponding age, but they were within the normal range in the patients with non-functional adrenal tumors. The serum DHEA-S level reflects the degree of suppression of the normal adrenal gland by cortisol hypersecretion from adrenal tumors. But the serum level of DHEA-S decreases with age, and because the normal range of serum DHEA-S is low in elderly subjects, we should be careful to evaluate the level of DHEA-S in elderly patients with adrenal Cushing's syndrome or ASCA. The immunohistochemical study showed DHEA-ST expression was noticeably suppressed in the adjacent adrenal cortex in ASCA and adrenal Cushing's syndrome. The decreased expression of DHEA-ST may reflect autonomous neoplastic cortisol secretion and subsequent ACTH suppression in ASCA and adrenal Cushing's syndrome. A single measurement of plasma ACTH or measurement of ACTH response to corticotropin-releasing hormone was not enough to screen for ASCA because of the wide variation among the cases. Dexamethasone suppression test is essential in identifying ASCA and also a single determination of serum DHEA-S is easy and may be useful for the screening of ASCA in adrenal incidentalomas in young and middle aged subjects, and is especially useful for outpatients.
由于成像技术的广泛应用，肾上腺偶发瘤的报告数量一直在增加。无症状分泌皮质醇的肾上腺腺瘤（ASCA）患者在无库欣综合征临床证据的情况下分泌皮质醇，这种情况比之前认为的更为常见，并且他们在肾上腺切除术后有肾上腺功能不全的风险。因此，应对偶发瘤患者进行皮质醇过度分泌的筛查。本研究的目的是发现一种简便的筛查试验以发现ASCA。我们调查了4例ASCA患者的激素谱，并与11例无功能肾上腺肿瘤患者和10例肾上腺库欣综合征患者进行了比较。我们还通过免疫染色研究了手术切除的附着非肿瘤性肾上腺组织中脱氢表雄酮硫酸转移酶（DHEA-ST）的表达，其被认为代表下丘脑-垂体-肾上腺轴的抑制程度。所有ASCA患者和肾上腺库欣综合征患者的血清硫酸脱氢表雄酮（DHEA-S）水平均低于相应年龄的健康受试者，但无功能肾上腺肿瘤患者的DHEA-S水平在正常范围内。血清DHEA-S水平反映了肾上腺肿瘤皮质醇过度分泌对正常肾上腺的抑制程度。但血清DHEA-S水平会随年龄下降，并且由于老年受试者血清DHEA-S的正常范围较低，我们在评估老年肾上腺库欣综合征或ASCA患者的DHEA-S水平时应谨慎。免疫组化研究表明，ASCA和肾上腺库欣综合征患者相邻肾上腺皮质中DHEA-ST的表达明显受到抑制。DHEA-ST表达的降低可能反映了ASCA和肾上腺库欣综合征中肿瘤自主性皮质醇分泌及随后促肾上腺皮质激素（ACTH）的抑制。由于病例之间差异较大，单次测量血浆ACTH或测量ACTH对促肾上腺皮质激素释放激素的反应不足以筛查ASCA。地塞米松抑制试验对于识别ASCA至关重要，并且单次测定血清DHEA-S简便易行，可能有助于筛查年轻和中年受试者肾上腺偶发瘤中的ASCA，对门诊患者尤其有用。
