促纤维增生性小圆细胞瘤的光学显微镜及电子显微镜观察

The light and the electron microscopic observation of desmoplastic small round cell tumor

目的 :研究促纤维增生性小圆细胞瘤 (desmoplasticsmallroundcelltumor,DSRCT)的组织病理学及超微结构特点。方法 :3例DSRCT进行HE光镜、免疫组化染色 ,2例进行透射电镜观察。结果 :瘤细胞呈不规则的大小不一的巢团和梁索状结构并埋没在增生的纤维结缔组织中 ;免疫组化显示瘤细胞具有上皮源性、间质性和神经源性等多向分化的特点 ;电镜特征性结构为多数瘤细胞胞浆内核旁区有大小不等的中间丝聚集物 ,呈小球形或螺纹状排列 ,有的中间丝占据胞浆的较大比例。结论 :DSRCT具有特殊的组织学、免疫组化及超微结构特征 。

Objective : This paper was to study the histopathologic and ultrastructural features of desmoplastic small round cell tumor (DSRCT). Methods : Three cases of DSRCT were observed by HE light microscopy and immunohistochemical method, and two of three cases were studied by electron microscopy. Results:The characteristic histological pattern of nests of small undifferentiated cells embedded in a dense fibrous stroma was seen in all of cases. This tumor showed immunohistochemical feature of epithelial, mesenchymal as well as neural multidirectional differentiation. Ultrastructural finding was the presence of paranuclear cytoplasmic aggregates of intermediate filaments, which varied greatly from case 1 to case 2 and within the same tumor. In some cells, they appeared as only small aggregates, while in others they occupied a large portion of the cytoplasm and were often arranged in globular whorls. Conclusion: This tumor has distinctive histopathologic, immunohistochemical and ultrastructural features. The electron microscopy plays an important role in diagnosis and differential diagnosis of these tumors.