甲状腺显示胸腺样分化的癌6例临床病理分析

Clinicopathological analysis of 6 cases with thyroid carcinoma showing thymus-like differentiation

目的：探讨甲状腺显示胸腺样分化的癌（carcinoma showing thymus - like differentiation，CASTLE）的临床病理特征及鉴别诊断。方法：对6例 CASTLE 进行组织形态学观察及免疫组化标记，总结其临床资料和组织病理特征，检测抗体 CD5、CD117、p63、CK19、TG、TTF -1等。结果：本组6例患者皆为女性，平均发病年龄53岁，肿瘤直径3-6cm（平均4.5cm）。镜下瘤组织呈岛状、索状，被纤维组织分隔，间质及肿瘤细胞间可见淋巴细胞和浆细胞浸润，瘤细胞梭形，可见空泡核，核仁小，核分裂较少。免疫组化显示瘤细胞表达 CD5、CD117、p63、CK19等。结论：甲状腺 CASTLE 具有较独特的病理组织学改变和免疫表型，诊断依靠形态学特征，免疫组化标记有助于与甲状腺未分化癌、甲状腺鳞状细胞癌及转移性淋巴上皮癌等相鉴别。

Objective：To investigate the clinicopathological features and differential diagnosis of thyroid carcinoma showing thymus - like differentiation（CASTLE）. Methods：We summarized the clinical data and histopathological features by morphological observation and immunohistochemistry for 6 cases of CASTLE. To test CD5,CD117,p63, CK19,TG and TTF - 1. Results：All the 6 patients were female,and the average age was 53 years. The diameter of the tumors was 3 - 6 cm（average 4. 5 cm）. The tumor tissue,checked under the microscope,showed island - like or cord- like morphology,and was separated by fibrous tissue. The invation of lymphocytes and plasma cells to the mesen-chymal and tumor cells could be found. The tumor cells were spindle - like,accompanied with small nuclei. The vacu-ole nuclei were noticed,and nuclear fission was rarely seen. Immunohistochemistry results showed that the tumor cells expressed CD5,CD117,p63 and CK19. Conclusion：Thyroid CASTLE showed relatively unique pathological changes and immune phenotypes. The diagnosis relies on morphological features,and the immunohistochemical markers will be helpful with differential diagnosis of anaplastic thyroid cancer,thyroid squamous cell carcinoma and metastatic lymph epithelial cancer.