儿童胸腺淋巴上皮瘤样癌的临床病理分析

目的:探讨儿童胸腺淋巴上皮瘤样癌(lymphoepithelioma-like carcinoma,LELC)的临床病理学特征、免疫表型、诊断和鉴别诊断。方法:分析2例LELC患儿的临床表现、病理形态和免疫表型,并进行文献复习。结果:1例发生于6岁男童,1例发生于10岁女童,以发热、胸痛就诊。大体检查肿物结节状,有包膜,切面实性灰褐色,质软。组织学上肿瘤细胞呈巢状、条索状排列,肿瘤细胞合体样,细胞核大,空泡状,核仁明显,核分裂像易见,间质大量小淋巴细胞浸润。免疫组化标记显示CK、CK5/6、CK7、CK8/18阳性,OCT-4、SALL-4、GCP3、AFP阴性,淋巴造血细胞标记阴性。EB病毒原位分子杂交检查示EBV阳性。结论:LELC是儿童少见的肿瘤,根据临床病理学特征和免疫表型容易诊断,诊断需与生殖细胞肿瘤及淋巴瘤鉴别,患者预后较差。

Clinicopathological Analysis of Thymic Lymphoepithelioma-like Carcinoma in Children

ABSTRACT Objective: To study the clinicopathological features, immunophenotype and differential diagnosis of thymic lymphoepithelioma-like carcinoma(LELC) in children. Methods: Two cases of children with lymphoepithelioma-like carcinoma of thymus were retrieved from our institution. The clinical, radiological and pathological features were analyzed along with a literature review. Results: A boy and a girl with LELC were enrolled in this study. Grossly, cut surface of tumor appeared as the gray tissue lump detected. Histologically, the tumors were composed of undifferentiated large cells, either loosely or closely packed, with the nested and trabecular growth pattern. The tumor cells were generally oval or polygonal in shape, while the demarcation between the cells was indistinct and form the syncytial appearance. The nuclei were vesicular and had one or more prominent nucleoli. There were abundant infiltrates of lymphocyte and plasma cells among the tumor nests. The tumor cells showed positive expression of CK, Ki-67. The stromal lymphocytes mainly expressed CD3 and CD8. EBER was positive in the entire tumor cells. The follow up data, which terminated at June 2017, demonstrate 1cases was alive with tumor recurrent and 1 case lived 6 months after operation. Conclusion: Lymphoepithelioma-like carcinoma occurred of thymus in children is rare. It has distinctive morphologic features and poor prognosis. The accurate diagnosis is dependent on the combination of histologic and immunohistochemical examination.