甲状腺内胸腺癌临床病理学分析

Clinicopathologic analysis of intrathyroid thymic carcinoma

目的探讨甲状腺内胸腺癌(ITTC)的临床病理学特征、免疫表型和预后。方法回顾性分析ITTC患者的临床资料,包括一般临床资料、大体检查、组织学特征、免疫表型及EB病毒编码的小mRNA(EBER)原位杂交检测情况。结果纳入的9例患者肿瘤均为单发性病变,呈结节状。镜下可见肿瘤内大小不等的实性巢状、梁状结构,被间质致密的纤维组织分割成小叶状结构。肿瘤细胞呈多角形或短梭形,细胞界限不清。细胞质淡红染,细胞核圆形或卵圆形,空泡状,核仁明显。9例患者肿瘤均弥漫高表达CKAE1/AE3和CK5/6,不同程度表达CD5(弥漫表达或片状表达),8例患者表达CD117。5例患者肿瘤标本行EBER原位杂交检测,结果均为阴性。随访期间,1例患者失访;其余患者随访9~91个月,仅2例发生复发或转移。结论ITTC是一种罕见的甲状腺低度恶性肿瘤,具有独特的组织病理学特征和免疫表型,预后较好。CD5和CD117可作为ITTC诊断和鉴别诊断的标记物。

Objective To investigate the clinicopathological characteristics,immunophenotype,and prognosis of patients with intrathyroid thymic carcinoma(ITTC).Methods The clinical data of 9 cases with ITTC were retrospectively analyzed,including general clinical data,gross examination,histological features,immunophenotype and EBV-encoded small RNA(EBER)in situ hybridization.Results All of 9 cases had single lesions and nodular.Microscopically,the solid nest-like and beam-like structures with different sizes could be seen in the tumor,which were divided into lobular structures by dense interstitial fibrous tissues.The neoplastic cells were polygonal or short spindle shaped,and the cell boundaries were not well defined.The cytoplasm was reddish,the nucleus was round or ovoid,and the nucleolus was obvious.The diffusely high expression of CKAE1/AE3 and CK5/6 of tumors were found in 9 patients,with expression of CD5 in varying degrees(diffuse expression or fragmental expression),and the expression of CD117 were found in 8 patients.The tumor EBER in situ hybridization test results of 5 patients tested were all negative.During the follow-up,1 patient was lost to follow-up.Other patients were followed up for 9 to 91 months,and only 2 cases had recurrence or metastasis.Conclusion ITTC is a rare low-grade tumor of thyroid with distinct histopathological features,immunophenotype and good prognosis.CD5 and CD117 can be makers for the diagnosis and differential diagnosis of ITTC.