[Clinicopathological characteristics of Klinefelter syndrome: a testicular biopsy analysis of 87 cases].

Objective: To investigate the clinicopathological characteristics of testicular biopsies from Klinefelter syndrome (KS) patients. Methods: The testicular biopsy specimens of 87 patients with KS (a total of 107 biopsy specimens) were collected from the Department of Pathology, Peking University Third Hospital, Beijing, China from January 2017 to July 2022. All patients were diagnosed as KS by peripheral blood karyotyping analysis. The testicular histopathologic features, testicular volume and hormone levels were evaluated retrospectively. The histopathologic analysis was used to assess the quantity and morphology of Leydig cells, the spermatogenic state of seminiferous tubules, the thickening of the basement membrane of seminiferous tubules and the changes of stroma. Results: Leydig cell proliferative nodules were seen in 95.3% (102/107) of KS testicular biopsy tissues. The eosinophilic inclusion bodies and lipofuscin in Leydig cells were found in 52.3% (56/107) and 57.9% (62/107) of specimens, respectively. The Sertoli cell only seminiferous tubules and the hyalinized tubules were found in 66.4% (71/107) and 76.6% (82/107) of the examined tissues, respectively. The tubules with complete spermatogenic arrest were found in 15.9% (17/107) of specimens, and 5.6% (6/107) of the specimens showed low spermatogenesis or incomplete spermatogenic arrest. In 85.0% (91/107) of the specimens, increased thick-walled small vessels with hyaline degeneration were identified. Conclusions: The most common features of KS testicular specimens are Leydig cell proliferative nodules, hyaline degeneration of seminiferous tubules and proliferation of thick-walled blood vessels. Testicular biopsy specimens of KS are rare. The pathologists can make a tentative diagnosis of KS based on the histological findings, combined with the ultrasound and laboratory results, which is helpful for further diagnosis and treatment of KS.目的： 探讨Klinefelter综合征（Klinefelter syndrome，KS）患者睾丸活检标本的临床病理学特征。 方法： 收集北京大学第三医院病理科2017年1月至2022年7月共87例KS患者共107个睾丸活检标本，患者均经外周血染色体核型分析确诊为KS，对睾丸的病理组织学特征、睾丸体积及激素水平进行回顾性评价。分别从Leydig细胞的量和形态、生精小管生精状态和管壁增厚程度及间质变化等方面进行病理组织学评估。 结果： 95.3%（102/107）的KS睾丸穿刺组织中可见Leydig细胞增生结节。Leydig细胞内的嗜酸性包涵体和脂褐素分别见于52.3%（56/107）和57.9%（62/107）的送检组织。唯Sertoli细胞的小管和管壁玻璃样变的小管分别见于66.4%（71/107）和76.6%（82/107）的送检组织。完全生精阻滞的小管见于15.9%（17/107）的送检组织，5.6%（6/107）的送检组织中可见生精低下或不完全生精阻滞现象。85.0%（91/107）的送检组织中可见厚壁小血管的增多伴玻璃样变。 结论： KS的睾丸活检标本少见，其最常见的特征是Leydig细胞增生结节、生精小管的玻璃样变和厚壁血管的增生、玻璃样变。病理医师基于组织学表现，结合超声和实验室检查结果，可以作出KS的倾向性诊断，有助于KS的诊疗。.