本文报告8例恶性组织细胞病(简称恶组病)骨髓标本的电镜观察结果。电镜下见骨髓中颇多恶性组织细胞浸润,形态变异大,分化程度不一,以中等成熟者为主。表面常有胞质性突起。核可有凹陷甚至畸形,核仁较大,染色质疏松。各例均见核小体,2例出现Bouterille 4型核小体。3例的少数细胞有核泡,胞质中含溶酶体,高尔基复合体发达,滑面内质网有时过度发育,常见巨大或畸形线粒体。3例发现恶性巨细胞,核显著畸形或数目增多。较成熟的恶性组织细胞表面活动性更强,胞饮及吞噬活跃,常吞噬红 This article reports 8 cases of malignant histiocytosis (referred to as croup disease) bone marrow specimens observed by electron microscopy. Electron microscope see a lot of malignant cells in bone marrow infiltration, morphological changes, different degrees of differentiation, mainly to moderately mature. Surface often cytoplasmic processes. Nuclear depression may be deformity or even larger nucleoli, chromatin loose. In each case, nucleosomes were seen, and in 2 cases, Bouterille 4 nucleosomes appeared. A small number of cells in 3 cases had nuclear blisters, lysosomes in the cytoplasm, developed Golgi complex, sometimes over-development of the smooth endoplasmic reticulum, and common large or malformed mitochondria. Three cases found malignant giant cells, nucleus deformity or increased number. Mature malignant cells more surface activity, vitiligo and phagocytosis, often swallowed red