细胞蜡块和分子检测在恶性胸腔积液病理诊断中的应用

Application of cell wax block and molecular detection in the pathological diagnosis of malignant pleural effusion

目的探讨恶性胸腔积液制备细胞蜡块技术在病理诊断中的优势,并阐述其与免疫组化及分子检测相结合在实现个体精准化治疗中的运用价值。方法回顾性分析我院248例胸腔积液细胞学涂片及细胞蜡块的HE形态,评价细胞蜡块免疫组化的特点,并对80例标本行荧光定量微滴式数字PCR及二代测序NGS。结果与传统细胞学涂片及液基细胞学相比,胸水细胞蜡块细胞数量增多且具有一定的空间结构,免疫组化以CK7,NapsinA,TTF-1阳性最多见,提示肿瘤原发灶多为肺来源。常规细胞学组和细胞蜡块组诊断恶性胸腔积液的灵敏度、特异度及准确性分别为87%、75%、87%和99%、87%、99%。常规细胞学组与细胞蜡块组两种诊断方法一致性较差(Kappa值为0.269)。常规细胞学和细胞蜡块诊断之间具有显著差异(P<0.05)。46%(37/80)患者胸水细胞蜡块行ddPCR及NGS分子检测出现基因突变,主要为EGFR、PD-L1、KRAS和TP53等,其中EGFR突变率分别约为34%。27%(7/26)患者PD-L1免疫组化结果示阳性。结论细胞蜡块技术在胸腔积液良恶性诊断及鉴别来源中具有重要的作用,不仅为基因检测提供了有价值的标本,并且提高了晚期癌症患者临床靶向治疗的可能性。

Objective To explore the advantages of cell wax block preparation technology in pathological diagnosis of malignant pleural effusion,and to describe its application value in combination with immunohistochemistry and molecular detection for individual precise treatment.Methods Hematoxylin(HE)morphology of 248 pleural effusion cytological smears and cell wax blocks in our hospital were retrospectively analyzed,and immunohistochemical characteristics of cell wax blocks were evaluated.Fluorescence quantitative droplet digital PCR and next-generation sequencing NGS were performed on 80 specimens.Results Compared with the traditional cytological smear and liquid based cytology,the number of pleural fluid cells in wax block was increased and had a certain spatial structure.CK7,NapsinA and TTF-1 were the most positive cells in immunohistochemistry,suggesting that the primary tumor was mostly pulmonary origin.The sensitivity,specificity and accuracy of conventional cytology and cell block cytology in the detection of malignant pleural effusion were 87%,75%,87%and 99%,87%,99%,respectively.The two diagnostic methods of the routine cytology group and the cell block group were poorly consistent(Kappa=0.269).There was significant difference between conventional cytology and cell wax block diagnosis(P<0.05).46%(37/80)of the patients had gene mutations detected by ddPCR and NGS,mainly EGFR,PD-L1,KRAS and TP53,among which EGFR mutation rate was about 34%.PD-L1 immunohistochemistry was positive in 27%(7/26)of the patients.Conclusion Cell wax block technology plays an important role in the diagnosis and differentiation of benign and malignant pleural effusion.It not only provides valuable specimens for gene detection,but also improves the possibility of clinical targeted therapy for advanced cancer patients.