黏液型脂肪肉瘤的CT诊断

CT Diagnosis of Myxoid Liposarcoma

目的探讨黏液型脂肪肉瘤(MLS)的CT表现和诊断价值。方法搜集经手术病理证实的18例MLS,对其大小、形态、边界、密度、内部结构及增强扫描特征进行回顾性CT影像分析,并探讨这些征象在诊断与鉴别诊断中的价值。结果 18例瘤体平均最大径12 cm;11例呈类圆形,7例呈不规则形;15例边界清晰,3例边界不清并侵犯周围肌肉;18例均表现为低密度肿块伴瘤内纤维分隔,其中4例伴软组织密度结节或肿块,7例伴脂肪密度灶,1例伴钙化灶,增强扫描不同程度不均匀强化。术后随访发现9例复发,其中5例伴发转移瘤,包括单纯肺外转移4例,肺内外转移1例。结论 CT在MLS的诊断与鉴别诊断中具有重要的价值。

Objective To investigate CT features of myxoid liposarcomas（MLS）,and to evaluate these features in making diagnosis.Methods Eighteen cases with pathologically-proved myxoid liposarcoma were selected.The size,morphology,margin,density,internal structure and enhancement characteristics of the lesions on CT scans were retrospectively analyzed.The diagnostic value of these signs was assessed.Results The average maximal diameter of the lesions was 12 cm in all cases.The lesions were oval（n=11） or irregular（n=7） in shape.Distinct margin was seen in 15 cases,while indistinct margin with invasion of adjacent muscles in 3 cases.In all cases the tumor presented as low-density mass with intratumoral fibrous septum and showed heterogeneous enhancement after contrast medium administration.Soft tissue nodule or mass was seen in 4 cases.Fatty tissue was seen in 7 cases and calcification was seen in 1 case.Recurrence was observed in 9 cases during the follow-up period,and 5 of them developed metastases, including pure extrapulmonary metastases（n=4） and combination of intra-pulmonary and extra-pulmonary metastases（n=1）.Conclusion CT plays an important role in diagnosing and differentiating myxoid liposarcoma.