目的　探讨促结缔组织增生性纤维母细胞瘤的临床病理学特征。方法　采用光镜观察和免疫组织化学染色 ,对 3例促结缔组织增生性纤维母细胞瘤进行组织形态学观察及免疫表型分析。结果　临床上分别表现为下肢内侧的深部软组织内及前臂和外踝部皮下组织内缓慢性生长的无痛性肿块。大体上 ,肿瘤境界清楚 ,质地坚韧。镜下观察显示 ,肿瘤由稀疏的梭形或星状纤维母细胞和大量致密或纤维粘液样的间质组成。瘤细胞的染色质细致 ,可见小核仁 ,细胞无异型性 ,也无核分裂 ,似“反应性”纤维母细胞。免疫组织化学标记显示瘤细胞表达波形蛋白 ,部分表达平滑肌肌动蛋白、肌特异性肌动蛋白和结蛋白。结论　促结缔组织增生性纤维母细胞瘤是一种具有独特临床病理学特征的良性纤维母细胞性肿瘤 ,组织学上必须与一些良性或低度恶性的纤维母细胞性 (或肌纤维母细胞性 )病变作鉴别诊断 Objective To investigate the clinicopathological features of connective tissue proliferating fibroblastoma. Methods Light microscopy and immunohistochemical staining were used to observe the histomorphology and immunophenotype of 3 cases of connective tissue proliferating fibroblastoma. Results Clinically, the painless masses in the deep soft tissues of the lower limbs and in the subcutaneous tissues of the forearm and lateral malleolus were found to be slowly growing. In general, the realm of tumors is clear and the texture is tough. Microscopic observations revealed that the tumor consisted of sparse fusiform or stellate fibroblasts and a large number of dense or fibromyoid mesenchyme. The chromatin of the tumor cells was fine, showing small nucleoli, no abnormal cells, and no nuclear division, like “reactive” fibroblasts. Immunohistochemical markers showed that the tumor cells expressed vimentin and partially expressed smooth muscle actin, muscle-specific actin, and desmin. Conclusions The connective tissue proliferating fibroblastoma is a benign fibroblast tumor with unique clinical pathological features. Histologically it must be associated with some benign or low-grade fibroblasts (or myofibroblasts). Lesions for differential diagnosis