肺原发性小细胞未分化癌占肺癌的20—30％,其生物学性质特殊,恶性程度高,转移早。因此,对每一例进行准确的病理组织学诊断是极为重的,由于支纤镜活检中,组织均有不同程度的挤压变形,严重时呈致密梭形索状,给诊断造成极大困难,故我们对小细胞肺癌支纤镜活检开展半薄切片研究,并辅以免疫组织化学染色,提高小细胞未分化癌的诊断率。 38例中除10例经常规切片确诊外,10例可疑小细胞癌经回顾性半薄切片观察确定诊断,18例常 Pulmonary primary small cell undifferentiated cancer accounted for 20-30% of lung cancer, its special biological characteristics, high degree of malignancy, early metastasis. Therefore, it is very important to perform accurate histopathological diagnosis for each case. Due to the fiberoptic biopsy, the tissues are deformed to varying degrees, and when severe, they are dense fusiform cords, which makes it difficult to diagnose. Therefore, we conducted semi-thin section biopsy of small cell lung cancer with microscopy and supplemented with immunohistochemical staining to improve the diagnostic rate of small cell undifferentiated carcinoma. Of the 38 cases, except 10 cases diagnosed by routine slicing, 10 cases of suspected small cell carcinoma were diagnosed by retrospective semi-thin section observation, and 18 cases were often diagnosed.