目的探讨骨外黏液样软骨肉瘤(EMC)的临床病理学特征。方法报道2例EMC的组织形态学和免疫组化特征,结合文献对其病理诊断和鉴别诊断进行分析。结果 2例EMS分别发生于左侧腹壁和右臀部。光镜下肿瘤呈多结节状,结节又分隔成大小不等的小叶,类圆形、梭形、星芒状肿瘤细胞包埋于黏液样基质中,肿瘤细胞具轻度异型性。免疫组化示vimentin和S-100为(+),Ki-67阳性率<2%。结论 EMC分为分化好的普通型和分化差的细胞型,两型均具有特异的组织学和细胞遗传学改变,免疫表型特异,Ki-67阳性率对预后有影响。 Objective To investigate the clinicopathological features of extranodal mucinous chondrosarcoma (EMC). Methods Two cases of EMC histomorphology and immunohistochemistry were reported, and the pathological diagnosis and differential diagnosis of the two cases were analyzed. Results 2 cases of EMS occurred in the left abdominal wall and right hip. The tumors were nodular under light microscope. The nodules were separated into small leaflets of different sizes. The round, fusiform, stellate tumor cells were embedded in the mucoid matrix, and the tumor cells were slightly atypia. Immunohistochemistry showed vimentin and S-100 (+), Ki-67 positive rate of <2%. Conclusion EMC is divided into well differentiated common type and poorly differentiated cell type. Both types have specific histological and cytogenetic changes. The immunophenotype is specific and the positive rate of Ki-67 has an impact on prognosis.