目的探讨软组织未分化多形性 肉瘤(UPS)各亚型的CT与MRI表现及其组织 病理学基础。方法 回顾性分析经手术病 理证实的32例软组织UPS患者临床、影像 及病理资料。结果 32例软组织UPS按照组 织病理学分为三种亚型：①高级别UPS 27 例; ②巨细胞UPS 3例; ③炎症性UPS 2 例。32例软组织UPS均呈分叶状或不规则 长圆形，27例高级别UPS及3例巨细胞UPS 均密度/信号不均匀，常伴囊变、坏死及 出血，边界模糊，增强扫描实质部分呈 轻、中度不均匀强化；2例巨细胞UPS出 血、囊变。2例炎症性UPS边界清楚，出血 和囊变不明显；增强后仅有轻微强化。结 论 软组织未分化多形性肉瘤的CT与MRI表 现多样性，与其不同亚型的病理学基础密 切相关，炎症性UPS的影像表现不典型, 确诊需依靠病理检查。

Objective To investigate CT and MR appearances of undifferentiated pleomorphic sarcoma in soft tissue, in order to improve diagnostic accuracy. Methods CT and MR images of 32 patients with histologically proved UPS were reviewed, CT and MR imaging findings were correlated with histologic findings. Results Of the 32 UPS cases, There were three different pathological subtypes: ①high grade type 27 cases; ②giant cell type 3 cases; ③inflammatory type 2 cases. Undifferentiated pleomorphic sarcoma were lobulated or irregular Oval shape in all 32 lesions. 27cases with high grade (HG) type and 3cases with giant cell (GC) type, the masses showed heterogeneous density and signals with ill defined margin．Necrosis and cystic degeneration in tumors were often found. The solid component was markedly heterogeneous enhanced. 2 lesions accompanied by hemorrhage and cystic degeneration displayed in 3 cases with giant cell (GC) type. 2cases with inflammatory (In) type had clear border, hemorrhage and cystic degeneration in tumors were uncommmon found．the tumors enhanced slightly after contrast medium. Conclusion CT and MRI findings of undifferentiated pleomorphic sarcoma in soft tissue are varied, The imagings characteristics were different related to their different pathological subtype features, There are some characteristic manifestations in HG type and GC type. But In type do not have specific imaging signs, and the diagnosis need pathologic examination.