韧带样纤维瘤病的CT及MRI特征及病理对照

目的回顾性分析韧带样纤维瘤的CT及MRI特征表现及病理基础。方法收集经手术病理证实的韧带样纤维瘤共27例影像学及病理资料,CT检查12例,MRI检查14例,另1例行CT及MRI检查;全部病例均行增强扫描。结果27例共30个病灶,16个病灶发生于腹壁,14个病灶发生于腹壁外。形态：全部病灶均沿肌纤维长轴生长,20个呈梭形或类圆形,10个不规则形;7个边界较清,23个边界不清。与肌肉密度、信号相比：CT上10个病灶呈稍低密度,3个呈等密度,9个渐进性中度强化,4个不均匀性强化;T1WI上9个病灶呈等信号,9个病灶呈稍低信号;T2WI上15个呈高或稍高信号,3个呈混杂信号;STIR上均呈较高信号,15个内部见条片状低信号;增强扫描所有病灶不均匀性渐进性中度强化,其中12个内部条状斑片状的低信号未见明显强化。病理上肿瘤多呈浸润性生长,由纤维母细胞和肌纤维母细胞组成,内部见致密纤维组织及胶原组织,部分见黏液沉积。结论韧带样纤维瘤的CT、MRI表现有一定特征,肿瘤多呈浸润生长,瘤内出现特征性稍低密度或条带状低信号,无液化坏死区,渐进性中度强化。

CT and MRI appearance of desmoid-type fibromatosis with pathologic correlation

Objective To assess the CT and MRI appearance and pathologic features of desmoid type fibromatosis（DF）.Methods 27 patients with pathologically confirmed DF underwent contrast-enhanced CT（12） and MRI（14） with 1 patient having both CT and MRI examinations.Results Of 30 soft tissue DF,14 were located in extra-abdominal and 16 in abdominal wall muscles.All tumors presented as solid masses growing along the long axis of muscles.20 tumors were fusiform or round and 10 were irregular in shape.The margins were well-defined（7） or ill-defined（23）.On unenhanced CT,3 tumors were isodense and 10 hypodense relative to the muscle.After intravenous contrast injection,9 tumors showed moderate progressive enhancement and 4 tumors enhanced heterogeneously.On MRI,the lesions were homogeneously T1 isointense（9） or slightly hypointense（9）,slightly T2 hyperintense（15） or heterogeneous on T2-weighted images（3）.All lesions were hyperintense on STIR-weighted images with bands of low signal intensities in 15.Heterogeneous moderate progressive contrast enhancement was observed in all tumors with non-enhancing T1- and T2-hypointense bands in 12 tumors.Histopathology showed infiltration of fibroblasts and myofibroblasts with compact fibrous and collagen tissues as well as mucus sedimentation.Conclusion DF has CT and MRI features of ill-defined margin,low CT density or MR signal intensity without necrosis and progressive contrast enhancement.