下肢黏液型脂肪肉瘤磁共振成像表现与鉴别诊断

MRI findings and analysis of myxoid liposarcomain lower limbs

目的探讨下肢软组织内黏液型脂肪肉瘤(Myxoid liposarcoma,MLS)的磁共振成像(MRI)表现及鉴别诊断。方法 6例经病理证实的下肢MLS患者均行MRI平扫及增强扫描,观察和评价肿瘤的位置、深度、大小形态、边缘情况,是否侵犯邻近结构,以及信号强度与均匀性和强化表现。结果 3例MLS患者MRI以短T1、长T2信号为主;2例MRI呈等、长T1长T2信号;1例以长T1、长T2信号为主的混杂信号。组织学上以黏液成分为主、脂肪含量少的肿瘤,增强后可见均匀或不均匀强化和明显的间隔影。结论 MRI增强可对下肢软组织内MLS诊断及鉴别诊断提供一定的帮助。

Objective To investigate MRI features and differential diagnosis of myxoid liposarcoma （MLS） in lower limbs. Methods Imaging data of 6 cases with myxoid liposarcoma in lower limbs proved by pathology were retrospectively analyzed. All patients underwent MRI plain scan and Gd-enhanced scan. All imaging features of tumors were observed and evaluated, included the location, the depth, the size and the shape, the fringe characteristic, the involvement of neighbouring tissue, and signal intensity and homogeneity on plain and enhanced images of tumors. Results Tumors showed high signal intensity on Tl-and T2-weighted images in 3 cases, iso-and low-signal intensity on Tl-weighted images and high signal intensity on T2-weighted images in 2 cases ,long T1 and long T2 signal characteristic but mixed other signal in 1 case. Heterogeneous or homogeneous enhancement and obvious separation were observed in tumors with histological type composed mainly by myxoid tissue but a littler fat. Conclusion MRI Gd-enhanced scanning is helpful in diagnosis and differentiation of myxoid liposarcoma in soft tissue of lower limb.