Scheithauer B W, Moschopulos M, Kovacs K, Jhaveri B S, Percek T, Lloyd R V
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota 55905, USA.
Endocr Pathol. 2005 Summer;16(2):133-8. doi: 10.1385/ep:16:2:133.
Klinefelter syndrome is a genetically determined primary gonadal defect characterized by the XXY karyotype. The testes are small, blood testosterone levels are low, and blood gonadotropin levels are elevated. Pituitary changes in patients with Klinefelter syndrome have not been evaluated in detail.
The first patient, a 76-yr-old man, was operated for a large sellar mass. The second and third patients, a 62- and a 52-yr-old man, respectively, died of cardiac failure. Both the latter pituitaries were normal-sized and removed at autopsy. The diagnosis of Klinefelter syndrome was confirmed by genetic testing in all three cases. The formalin-fixed and paraffin-embedded pituitaries of three patients were evaluated for adenohypophysial hormone immunoreactivity. For immunohistochemistry, the streptavidin- biotin-peroxidase (ABC) complex method was applied.
In case 1, histology and immunohistochemistry revealed an oncocytic gonadotroph macroadenoma immunoreactive for FSH and alpha subunit. No pituitary gland was evident. The pituitary of case 2 featured hyperplasia of gonadotrophs, some with features of "gonadal deficiency cells," and a microadenoma immunoreactive for GH. The pituitary of case 3 similarly showed hyperplasia of gonadotrophs and the formation of gonadal deficiency cells.
Protracted stimulation of gonadotrophs due to lack of androgen feedback might have been a factor in the formation of the gonadotroph adenoma in case 1 and in the development of gonadotroph hyperplasia in cases 2 and 3. The clinically silent GH microadenoma of case 2 was regarded as an incidental finding.
克兰费尔特综合征是一种由基因决定的原发性性腺缺陷，其特征为XXY核型。睾丸小，血液睾酮水平低，血液促性腺激素水平升高。克兰费尔特综合征患者的垂体变化尚未得到详细评估。
首例患者为一名76岁男性，因鞍区巨大肿块接受手术。第二例和第三例患者分别为一名62岁和一名52岁男性，死于心力衰竭。后两者的垂体大小正常，在尸检时被摘除。所有三例均通过基因检测确诊为克兰费尔特综合征。对三名患者经福尔马林固定、石蜡包埋的垂体进行腺垂体激素免疫反应性评估。免疫组织化学采用链霉亲和素-生物素-过氧化物酶（ABC）复合方法。
病例1中，组织学和免疫组织化学显示为嗜酸性促性腺激素细胞大腺瘤，对FSH和α亚基呈免疫反应性。未发现明显的垂体组织。病例2的垂体表现为促性腺激素细胞增生，部分具有“性腺功能减退细胞”的特征，以及一个对GH呈免疫反应性的微腺瘤。病例3的垂体同样显示促性腺激素细胞增生和性腺功能减退细胞的形成。
由于缺乏雄激素反馈导致促性腺激素细胞长期受到刺激，可能是病例1中促性腺激素细胞腺瘤形成以及病例2和病例3中促性腺激素细胞增生发展的一个因素。病例2中临床上无症状的GH微腺瘤被视为偶然发现。
