低分化横纹肌肉瘤的超微结构及诊断与鉴别诊断

The ultrastructural and differential diagnosis of poorly differentiated rhabdomyosarcoma

通过透射电子显微镜（ＴＥＭ）观察低分化横纹肌肉瘤（ＰＤＲＳ）的超微结构，并对电镜诊断标准及鉴别诊断进行探讨。ＴＥＭ下瘤细胞弥漫分布，以未分化间叶细胞为主，可观察到少数横纹肌分化细胞，其胞质已出现粗细肌丝，原始肌节和Ｚ带物质等特征性结构。我们认为，（１）原始肌节和Ｚ带物质是ＰＤＲＳ最可靠的超微结构诊断依据。（２）平行相间排列的粗细肌丝，横断面呈典型的点阵排列结构应是ＰＤＲＳ最低的诊断标准。本文对可能导致误诊为ＰＤＲＳ的恶性纤维组织细胞瘤中萎缩的横纹肌细胞进行比较观察，并对两者的鉴别进行了讨论。

The ultrastructure of the poorly differentiated rhabdomyosarcoma(PDRS) was observed by transmission electron microscope and the diagnostic standard are discussed. A few differentiated strited muscle cells was found among the undifferentiated mesenchymal cell.There were the thick and thin myofilaments,primary sarcomere and Z band structure in the cytoplasm.We believed that:1 primary sarcomere and Z band structure is the diagnostic standard reliablely. 2 the thick and thin myofilaments ought to be the basical diagnostic standard. At the same time,the atrophy strited muscle in the malignent fibrous histocytoma was observed as compared with PDRS and the differental diagnosis are discussed.