目的　探讨低度恶性纤维黏液样肉瘤 (LGFS)的临床病理特点、诊断和预后。方法　对 2例LGFS进行光镜、电镜、组化和免疫组化观察并结合文献进行分析。结果　肿瘤由纤维性区和黏液样区混合构成 ,二者呈交错相间排列 ;纤维性区瘤细胞呈旋涡状排列 ;黏液样区瘤细胞散在 ;细胞核轻度异型 ;PAS染色黏液样区和肿瘤细胞浆内均为阴性。免疫组化标记vimentin、NSE阳性。电镜观察瘤细胞呈纤维母细胞与肌纤维母细胞的特点。结论　LGFS是一种来源于纤维母细胞独立存在进展缓慢的低度恶性软组织肉瘤 ,易误诊为良性。病理诊断依赖于组织学、免疫组化和电镜观察 ,电镜在该瘤的诊断和鉴别诊断中具有重要价值 Objective To investigate the clinicopathological features, diagnosis and prognosis of low-grade fibrous myxomatoid sarcoma (LGFS). Methods Two cases of LGFS were observed by light microscopy, electron microscopy, histochemistry and immunohistochemistry. Results The tumor consisted of a mixture of fibrotic and mucinous areas. The two were arranged in a staggered pattern; the fibrous area had whirlpools of tumor cells; the myxoid area had scattered tumor cells; the cell nucleus was mildly heterogeneous; the PAS stained mucinous area and tumor cells Intraplasma was negative. Immunohistochemical markers vimentin, NSE positive. Electron microscopy showed that the tumor cells were characteristic of fibroblasts and myofibroblasts. Conclusion LGFS is a kind of low-grade malignant soft tissue sarcoma derived from the independent progression of fibroblasts, which is often misdiagnosed as benign. Pathological diagnosis depends on histology, immunohistochemistry and electron microscopy. Electron microscopy has important value in the diagnosis and differential diagnosis of this tumor.