摘要目的 探讨乳腺浸润性微乳头状癌(IMPC) HER2免疫组织化学(IHC)染色的判读方法.方法 收集60例IMPC病例,制备组织芯片并行HER2 IHC和荧光原位杂交(FISH)检测.比较两种方法的检测结果,重点观察HER2基因扩增病例的IHC染色特点.结果 按照2007版美国临床肿瘤学会/美国病理医师学院HER2检测指南,成功受检的52例IMPC中HER2 IHC阴性(0/1+)40例,不确定(2+)12例.15例IHC 0病例的FISH检测均为阴性.25例IHC 1+的病例中,1例FISH检测为基因扩增,2例不确定,22例基因无扩增.IHC 2+病例的FISH检测结果均为基因扩增.13例基因扩增IMPC病例的IHC染色特点均为微乳头结构的肿瘤细胞连接面或基底侧胞膜着色,肿瘤细胞团外缘胞膜(即面向间质侧)不着色.12例呈胞膜强着色,1例中等着色.37例基因无扩增病例中,22例细胞连接面或基底侧胞膜有不同程度着色,其中15例着色少和弱,7例中等着色.结论 IMPC HER2 IHC染色特点是微乳头结构的肿瘤细胞连接面或基底侧胞膜线性着色,间质侧胞膜不着色,提示其IHC染色判读中应强调胞膜染色强度而不是染色的完整性.IHC染色中或强的情况下建议FISH检测确定基因扩增状态.

abstractsObjective To evaluate the standards of HER2 immunohistochemistry (IHC) interpretation in invasive micropapillary carcinoma of the breast (IMPC).Methods HER2 expression in 60 cases of IMPC was evaluated by IHC and fluorescence in situ hybridization (FISH) using TMA-based techniques.The characteristics between cases with HER2 IHC and HER2 gene amplification results were compared.Results Using 2007 American Society of Clinical Oncology/College of American Pathologist (ASCO/CAP) criteria,among the 52 cases that were successfully stained by IHC,40 were HER2 IHC negative and 12 were equivocal (2 +).Fifteen cases of HER2 IHC 0 were negative for amplification by FISH.Twenty-five cases with IHC 1 + were tested by FISH ; and of these,one showed HER2 amplification,2 were equivocal,and the others were not amplified.All cases of IHC 2 + showed HER2 amplification by FISH.IHC staining of HER2 was located at cell-cell membrane or basolateral membrane of micropapillary structure,but not in the cytoplasmic membrane facing the stroma in all 13 cases which were HER2 amplified,including 12 showing very strong staining and one showing moderate staining.Among the 37 non amplified HER2 cases,22 showed IHC staining at cell-cell membrane or basolateral membrane (including 15 weak staining and 7 moderate staining).Conclusions HER2 IHC detection in IMPC is characterized by staining at cell-cell membrane or basolateral membrane of the micropapillary structure,and absence of staining in the cytoplasmic membrane.It is suggested that interpretation of HER2 IHC staining should be based on membrane staining intensity,but not the completeness of the membrane staining in IMPC.It is suggested to determine the HER2 gene amplification status by using FISH when IHC staining shows moderate or strong intensity.