免疫组化在肺小细胞癌支气管镜活检标本鉴别诊断中的应用

目的探讨免疫组化在肺小细胞癌和鳞状细胞癌鉴别诊断中的作用。方法应用免疫组化SP法,选择支气管镜活检标本病理形态疑似SCLC与低分化SCC共29例,检测CD56、PAX-5、TTF1、CgA、Syn、CK5/6及P63蛋白表达,分析SCLC的病理形态特征和免疫表型特点及其与SCC的鉴别。结果 29例支气管镜活检标本形态学观察SCLC与低分化SCC常有形态学重叠。免疫组化蛋白表达,CD56阳性21例,PAX-5阳性15例,TTF1阳性21例,CgA和（或）Syn阳性19例,CK5/6阳性8例,P63阳性9例。标记后诊断SCLC共21例,诊断低分化SCC共8例。分析SCLC与SCC的蛋白表达,各项指标均存在显著差异（P〈0.001）。结论 SCLC与SCC的蛋白表达存在显著差异,联合检测多种免疫组化指标,能够准确鉴别这两种类型的肺癌。

Application of Immunohistochemistry in Biopsy Specimen by Bronchoscope for Differential Diagnosis of Small Cell Lung Carcinoma

Objective To interprate the role of Immunohistochemistry in the differential diagnosis between small cell lung carcinoma（SCLC） and squamous cell cancer（SCC）.Methods protein expression of CD56、PAX-5、TTF1、CgA、Syn、CK5/6 and P63 in 29 brochonscopic specimens with suspected SCLC and low-differentiated SCC was examined by immunohistological SP method to analyze the pathological-characteristics,immunological phenotypical features and differentialdiagonosis between SCLC and SCC.Results of the 29 bronchoscopic biopsy samples,twenty-one were SCLC,eight were SCC,and there was usually morphological overlapping between SCLC and poorly differentiated SCC.Of the 21 cases with postive CD56 expression,twenty cases showed positive in SCLC and one with weakly positive in SCC;Of the 15 cases with PAX-5,thirteen cases demonstrated as positive in SCLC and two with weakly positive in SCC.Of the twenty-one cases with positive TTF1,twenty cases showed as positive in SCLC and one with weakly positive in SCC;of the nineteen cases with positive CgA and/or Syn,seventeen demonstrated as positive in SCLC and two with weakly positve in SCC;All indices showed significant difference between SCLC and SCC.Conclusion there is significant difference in the protein expression spectrum between SCLC and SCC,and multiple immunohistologic indices detection can be used for accurate differentiation for the two types of lung cancer.