目的总结鼻窦低度恶性肌纤维 母细胞肉瘤(low grade myofibroblastic sarcoma，LGMS)的影像学表现，以期提高 对该病的诊断水平。资料与方法 回顾性 分析经手术后病理证实的5例LGMS的影像 学表现。5例LGMS均行CT平扫，其中1例行 CT增强扫描，其余4例行MR平扫+增强扫 描。结果 5例LGMS，2例累及右侧上颌窦 及筛窦，2例累及双侧筛窦及蝶窦，1例累 及左侧各鼻窦。5例均表现为窦腔内不规 则形软组织肿块，CT平扫均呈等或稍低密 度；MRI检查，T1WI为中等及稍低信号， T2WI为中等及稍高信号，信号不均匀；增 强扫描5例均可见中度-明显强化。5例肿 瘤周围均出现虫蚀样溶骨性骨质破坏。结 论 鼻窦LGMS的影像学表现为鼻窦内软组 织肿块伴溶骨性骨质破坏，增强扫描中 度-明显强化，影像学检查有助于确定肿 瘤的的侵犯范围。

Objective To evaluate the image features of low-grade myofibroblastic sarcoma(LGMS) of paranasal sinus, and improve the diagnostic accuracy. Materials and Methods A retrospective analysis of 5 cases of paranasal sinus LGMS was carried out. Of the 5 patients, all of them underwent common CT, 1 patient underwent contrastenhanced CT and 4 underwent common MRI and contrast-enhanced MRI. Results Of the 5 patients, 2 occurred in the right maxillary sinus and ethmoidal sinus, 2 occurred in the sphenoid sinus and ethmoidal sinus, 1 occurred in all of the left paranasal sinus. CT scan showed hypo-indense and iso-indense soft tissue mass in the paranasal sinus. T1WI showed isointense mass and T2WI showed isointense and hyperintense mass. Contrast images showed moderate-obvious homogeneous enhancement. All of the 5 cases showed bone destruction. Conclusion LGMS of the paranasal sinus can be characterized as a soft tissue mass with bone destruction, but it is difficult to differentiate from other malignant diseases. Image features can help to determine the extent of the lesion.