头颈部显示胸腺样分化的癌临床病理学分析

Clinicopathologic characteristics of head and neck carcinoma showing thymus-like element

目的 探讨头颈部显示胸腺样分化的癌（carcinoma showing thymus like elements,CASTLE）的细胞学特点及临床病理特征.方法 收集7例CASTLE患者存档资料,行细胞学、组织学观察及免疫组织化学（LASB法）染色,采用突变扩增阻滞系统（ARMS）法检测BRAFV600E基因突变,并采用EBER原位杂交检测EB病毒感染情况,分析其细胞学特点及临床病理特征.结果 7例患者,5例女性,2例男性.年龄49～78岁,平均年龄65.6岁.6例位于甲状腺内,1例位于下咽.7例均为孤立性结节,边界相对清楚.肿瘤直径1.7～4.1 cm,平均直径3.0 cm.4例（含下咽病例）伴有颈部淋巴结转移.7例均有随访.1例于甲状腺内原位复发,并行甲状腺细针穿刺.其余6例均未发现复发和转移.1例CASTLE局灶性表达CD5（小于5%肿瘤细胞）,30%肿瘤细胞表达突触素,其余6例CASTLE弥漫阳性表达CD5.所有病例阳性表达CK5/6、p63、CD117,不表达甲状腺转录因子1、甲状腺球蛋白、CT.Ki-67阳性指数在3%～90%.6例均无BRAFV600E基因突变.6例EBER原位杂交均为阴性.结论 位于下咽CASTLE具有和甲状腺内CASTLE相同形态学特点和免疫组织化学表型.CD5和CD117是诊断CASTLE的有效指标.CD5阴性的CASTLE可伴神经内分泌分化.CASTLE的Ki-67阳性指数可以较高,在淋巴上皮癌型CASTLE中尤为明显.BRAFV600E基因突变和EB病毒感染可能不参与CASTLE的发生.

Objective To investigate clinicopathological features of carcinoma showing thymus-like elements （ CASTLE） in the head and neck regions. Methods Clinicopathological data of 7 patients with CASTLE in the head and neck regions were retrospectively reviewed. Immunohistochemical staining and in situ hybridization for EBER were performed. BRAFV600E mutation was examined by ARMS method in 6 cases. Results There were 5 females and 2 males with age between 49 and 78 years （ average of 65. 6 years） . All tumors were solitary nodular lesions with an infiltrative border, including 6 intrathyroid tumors and 1 extrathyroid tumor in the laryngeal pharynx. The tumors were 1. 7-4. 1 cm in diameter （ average of 3. 0 cm） . Four cases demonstrated lymph node metastasis. All patients were alive without metastasis during follow-up, except one consultation case （ with FNA sample） developed recurrence at the primary site. The cases showed different immunoreaction to CD5, diffuse immunoreaction with p63, CK5/6 and CD117, but negative staining for TTF1, TG and calcitonin. One case showed positive immunoreaction with Synin less than 30% tumor cells. The Ki-67 labeling index was between 3% and 90%. No BRAFV600E mutation and EB virus infection were detected. Conclusions Extrathyroid CASTLE involving laryngeal pharynx shows the similar morphological and immunohistochemical features with intrathyroid CASTLE. Immunohistochemical markers of CD5 and CD117 are helpful in the diagnosis. Ki-67 labeling index can be high in CASTLE, especially in lymphoepithelioma type. CD5-negative CASTLE may have neuroendocrine differentiation. BRAFV600E mutation and EB virus may not be involved in the carcinogenesis of CASTLE.