腹膜后脂肪肉瘤的CT表现及病理对照

目的 结合病理探讨腹膜后脂肪肉瘤及其不同组织学亚型的CT表现特点，以加深对该病的认识。资料与方法 回顾性分析22例28例次（原发11例次，复发17例次）原发于腹膜后区脂肪肉瘤的CT资料，术前CT表现与复核病理切片对照，分析不同组织类型脂肪肉瘤的CT表现与病理的相关性。结果 与病理对照。脂肪瘤样脂肪肉瘤（LLS）4例，黏液样脂肪肉瘤（MLS）1例，圆细胞性脂肪肉瘤（RCLS）1例，去分化脂肪肉瘤（DDLS）2例，混合性成分20例。CT图像上，LLS表现为脂肪密度肿块，不均质，有分隔；MIS平扫表现为均匀的水样密度肿块。增强扫描可见网状，片状或岛状强化；RCLS表现为无脂肪的软组织肿块。与其他类型的软组织肿瘤难以鉴别；DDLS表现为明显强化的软组织肿块，常伴有分化良好的脂肪瘤样组织。结论 不同组织学亚型的脂肪肉瘤其CT表现有所不同，CT表现的差异取决于病7变内不同组织学亚型的比例。分布及混合的方式，本组中，腹膜后脂肪肉瘤多以混合形式存在，了解这些CT表现特点有助于脂肪肉瘤的术前诊断及分型。

Retroperitoneal Liposarcoma: A Comparison of CT Findings with Pathology

Objective To study CT features of retroperitoneal liposarcoma and its different histological subtypes by comparing with the pathological findings, and to make a further understanding of the disease.Materials and Methods CT findings in 22 patients (total 28 case times, including 11 initial and 17 recurrent case times) with primary retroperitoneal liposarcoma were retrospectively analyzed. Preoperative CT findings were compared with pathological results. The correlation of CT signs of different histological liposarcoma with pathology was studied.Results Pathologically, lipoma like liposarcoma (LLS) was seen in 4 patients, while myxoid (MLS) in one, round cell (RCLS) in one, dedifferentiated in 2 (DDLS) and mixed in 20. On CT scans, LLS showed heterogeneous fat density with septum shadow, and MLS presented water density with reticular or island like enhancement on enhanced scans. RCLS displayed as soft tissue mass containing no fat, which was difficult to be differentiated with other soft tissue tumors. DDLS was demonstrated as markedly enhanced soft tissue mass often containing well differentiated lipoma like tissue.Conclusion Retroperitoneal liposarcoma of different histologic subtype carries each own CT characteristics. The CT features depend on the proportion, distribution and mixed pattern of different components within the lesion. Mixed type is most often seen in this study. The knowledge of liposarcoma's CT manifestations is helpful for the preoperative diagnosis and classification of the disease.