细支气管肺泡癌核内包涵体的电镜及免疫组化分析

Ultrastructural and immunohistochemical features of nuclear inclusions in bronchioloalveolar carcinoma

目的探讨细支气管肺泡癌的核内包涵体超微结构特点和免疫原性。方法手术切除31例细支气管肺泡癌的肿瘤样本,应用SP-A和TTF-1单克隆抗体做免疫组化检测;肿瘤细胞中的核内包涵体数>5%的病例计为阳性,并结合电子显微镜观察。结果免疫组织化学结果,有6例肿瘤细胞核呈SP-A和TTF-1抗体双阳性;电镜观察结果,SP-A阳性的核内包涵体由弥散型或/和球型的细碎颗粒状物质组成,其内常夹杂一些不整形的折叠状膜样结构,核内包涵体常借膜样结构与内层核膜相连。结论细支气管肺泡癌的核内包涵体免疫组织化学呈SP-A阳性;超微结构上核内包涵体分为弥散型和球型,两者都由与SP-A有交叉抗原性的蛋白产物构成;蛋白产物在核周池内异常聚积,由内层核膜包被或与内层核膜部分相连,以伪包涵体的形式向核内演变成核内包涵体。

Purpose To investigate the fine structural nature of nuclear inclusions which are immunopositive for surfactant apoprotein-A （SP-A）. Methods Surgically resected tumor specimens from 31 patients were examined by immunohistochemistry,focused on reactivity to SP-A and thyroid transcription factor-1 （TTF-1） antibodies.Only cases with 5% positive nuclear inclusions in cancer cells were counted as positive,some of which were examined with electron microscope. Results Immunohistochemically,six of 31 cases were doubly positive for SP-A and TTF-1 antibodies. On electron microscopy,SP-A positive nuclei contained diffuse or globular type of fine granular substance. Both types of inclusions sometimes were connected with the inner nuclear membrane,in association with fragmented or stacked membranous structures. Conclusions The nuclear inclusions positive for SP-A antibody staining in bronchioloalveolar carcinomas of the lung are derived from accumulated content of perinuclear cisternae resembling pseudo-inclusion processes and composed of proteins antigenically cross-reactive with SP-A antibody.