少见部位孤立性纤维性肿瘤的影像学表现

Imaging Features of Solitary Fibrous Tumor in Rare Sites

目的探讨少见部位孤立性纤维性肿瘤(SFT)的影像学表现,以提高对该病的诊断水平。方法回顾性分析经病理证实的33例少见部位SFT患者的临床及影像学资料,分析其影像学表现。结果病变位于中枢神经系统10例,头颈3例,肺及纵隔9例,胰腺1例,泌尿生殖系统3例,腹盆腔及腹膜后5例,脊柱及四肢2例。所有病灶均为单发,多为圆形或类圆形(28/33)、边界清楚(24/33);X线平片示肿块呈稍高密度;CT平扫呈等密度或混杂密度(26/30)、钙化少见(4/30);病变在T_(1)WI上呈等或稍低信号(15/17),T_(2)WI信号不一;DWI弥散受限呈混杂高信号(9/9);CT增强扫描所有病灶表现为明显或中度不均匀强化,11/24见供血动脉或迂曲血管影;MRI增强扫描3例表现为"快进慢出"样强化,4例呈不均匀渐进性强化,10例似"地图"样不均匀明显强化,3/17见流空血管影。结论少见部位SFT的影像学表现与胸膜SFT相似,为孤立性圆形或类圆形肿块,边界清楚,CT平扫多为等或混杂密度,T_(1)WI为低至等信号,T_(2)WI为"黑白混杂"或"阴阳"表现,增强呈"地图"样不均匀明显强化。

Objective To explore the imaging features of Solitary fibrous tumor(SFT)in rare sites to improve its diagnostic accuracy.Methods Retrospectively analyzed the clinical and imaging data of 33 patients with SFT confirmed by pathology,and summarized their imaging characteristics.Results The lesions were located in the central nervous system(n=10),head and neck(n=3),lung and mediastinum(n=9),pancreas(n=1),genitourinary system(n=3),abdominal pelvic cavity and retroperitoneum(n=5),spine and limbs(n=2).All 33 cases were solitary.Among the 33 cases,84.8%of the masses were round,72.7%were well-defined.The X-ray showed hyperdensity.On plain CT scan,86.7%showed isodensity or mixed-density,only 13.3%could see calcification.The lesions showed isointense and mildly hypointense signal on T_(1)WI.And the signal was variable on T_(2)WI.9 cases had heterogeneous hyperintensity on DWI.All lesions demonstrated marked or moderate heterogeneous enhancement on contrast-enhanced CT scans.45.8%had a tortuous vascularsupply.On MRI,4 cases showed heterogeneous progressive enhancement,13 manifested geographic changes,17.6%showed flow void vessels.Conclusion Solitary fibrous tumor in rare sites has common imaging features with those of pleural SFT.It shows isodensity or mixed-density on CT images,andisointensity to hypointense signal intensity on T_(1)-weighted images.The signal intensity was heterogeneous on T_(2)-weighted images,so-called black-and-white mixed pattern or yin-yang appearance.It shows marked heterogeneous enhancement on contrast-enhanced CT and MRI,which manifested as geographic changes.