摘要目的：探讨两种细胞间黏附分子EpCAM及E－cadherin在甲状腺乳头状癌中的表达及其与患者临床病理指标的关系。方法免疫组织化学PV 6000非生物素法检测EpCAM及E－cadherin在91例甲状腺乳头状癌及24例甲状腺乳头状增生中的表达。结果（1）EpCAM在24例甲状腺乳头状增生病例均呈一致胞膜表达，在91例甲状腺乳头状癌，均有胞质表达100％（91／91），其中36．3％（33／91）同时有细胞核表达。 E－cadherin在24例甲状腺乳头状增生病例，亦呈胞膜阳性表达100％（24／24），而在84．6％（77／91）甲状腺乳头状癌中表达较癌旁正常组织有下调。（2） EpCAM细胞核阳性的33例中，同时伴有E－cadherin低表达的病例为30例，二者呈显著正相关（ P＝0．000， Spearman相关系数＝0．857）。（3） EpCAM在细胞核阳性表达与甲状腺癌滤泡亚型及甲状腺外浸润有关，分别P＝0．037和0．033，E－cadherin在甲状腺乳头状癌中低表达与年龄≥45岁及淋巴结转移相关（P＝0．018和0．010）。结论 E－cadherin在甲状腺乳头状癌中呈现低表达，表达较癌旁正常组织及乳头状增生组织有下调。 EpCAM在甲状腺乳头状增生及甲状腺癌中表达由细胞膜转移到细胞质，甚至部分到细胞核。联合检测这两种指标可为研究甲状腺乳头状癌的浸润及转移机制及评判其生物学行为提供有价值的参考。

abstractsObjective To study the expression of EpCAM and E-cadherin in papillary thyroid carcinoma and to analyze its correlation with various clinicopathologic parameters.Methods Immunohistochemical study for EpCAM and E-cadherin was carried out in 91 cases of papillary thyroid carcinoma.Twenty-four cases of papillary hyperplasia of thyroid were used as controls.Results In all of the 24 cases of papillary hyperplasia, EpCAM was located on the cell membrane, while in the 91 cases of papillary thyroid carcinoma studied, EpCAM was located within the cytoplasm, with 36.3% ( 33/91 ) showing nuclear localization as well.In all the papillary hyperplasia cases studied, E-cadherin showed membranous expression.E-cadherin expression was reduced in 84.6% ( 77/91 ) of papillary thyroid carcinoma, as compared with the surrounding native thyroid parenchyma.Amongst the 33 cases of papillary thyroid carcinoma which showed nuclear localization of EpCAM, 30 cases also showed reduced E-cadherin expression.There was a positive correlation between nuclear expression of EpCAM and loss of E-cadherin expression ( P=0.000; Spearman correlation coefficient=0.857).Nuclear expression of EpCAM correlated with follicular variant of papillary thyroid carcinoma and presence of extrathyroidal extension (P=0.037 and 0.033, respectively).Loss of E-cadherin expression correlated with age of patients and presence of lymph node metastasis ( P=0.018 and 0.010, respectively).Conclusions E-cadherin expression is reduced in papillary thyroid carcinoma, as compared with native thyroid parenchyma and papillary hyperplasia.Papillary thyroid carcinoma shows loss of EpCAM membranous expression and increased cytoplasmic/nuclear accumulation.Detection of these two markers may provide a valuable reference in defining the biologic behaviors of papillary thyroid carcinoma, including extrathyroidal extension and lymph node metastasis.