孤立性纤维性肿瘤的影像表现

Imaging findings of solitary fibrous tumors

目的探讨孤立性纤维性肿瘤（SFT）的影像表现。方法回顾性分析经手术病理证实的11例sPr的影像表现，其中行CT检查者8例，7例行增强检查；4例行MR检查，2例行增强扫描；1例同时行cT和MR检查。将影像表现与手术病理结果对照观察。结果（1）11例SFT中，位于胸部2例，腹盆腔5例，软组织4例。肿瘤直径2．5—23．0cm，平均11．8cmo肿瘤呈类圆形或椭圆形4例，形态不规则7例。边界清楚者8例，边界不清或部分不清者3例。（2）cT平扫密度不均匀，均可见低密度区，2例见高密度出血灶，1例瘤内点状钙化。（3）MRT，wI呈等信号，3例肿瘤T2wI呈略高信号，1例呈低信号。4例均见丰富的血管流空信号。3例瘤内信号混杂，其中2例散在长T1、长T2信号区，1例位于肝脏内见高信号出血灶；1例位于眼眶信号较均匀。（4）增强扫描9例病灶动脉期不均匀强化，并可见多发迂曲血管影；静脉期呈进行性或持续强化，并有斑片状无强化区。（5）显微镜下肿瘤由疏密不均的梭形细胞、致密胶原间质以及大量“鹿角样”薄壁血管组成。结论影像上见孤立性、边界清楚的软组织肿块，密度不均，增强扫描不均匀强化，静脉期持续强化，应考虑到SFT可能。

Objective To investigate the imaging characteristics of solitary fibrous tumor （SFT）. Methods This study included 11 cases with SFT proved by pathological results. The imaging manifestations were retrospectively reviewed and analyzed in comparison with surgical and pathological results. Among them, 8 patients underwent CT plain scan （1/8） or enhanced scan （7/8） , 4 patients underwent MR plain scan （2/4） or enhanced scan （2/4）, and only 1 patient underwent both CT and MR scan. Results （ 1 ） SFT were located in the thoracic cavity（2/11）, abdominal and pelvis （5/11）, and somatic soft tissues （4/11）. The average tumor size was 11.8 cm （2. 5 to 23.0 cm）. Among them, 4 tumors were round or ellipse, and 7 tumors were irregular. Eight tumors had well-defined contours, and the others showed illdefined contours. （2）On CT scan, all SFTs showed inhomogeneous density with low density areas. Calcification was seen in 1 case, and hemorrhagic foci were detected in 2 cases. （ 3 ） On MR scan, all SFFs showed intermediate signal intensity on T1WI. Three tumors were slightly hyperintense and the other was hypointense on T2 WI. All of them were rich of vascular signal voids. Three tumors,including 2 tumors with scattered long T1 and T2 signal and 1 tumor in the liver with hyperintense haemorrhage, displayed inhomogeneous mixed signal. One tumor in the orbit showed homogeneous signal. （4） On enhanced scan, 9 tumors showed irregular enhancement with multiple circuitous vessels in the arterial phase, and continuous or progressive enhancement with patch non-enhanced areas in the venous phase. （ 5 ） Histologically, SFTs were composed of juxtaposed hyper- and hypo-cellular spindle cells, dense eollagenous stromas and numerous thin-walled blood vessels with a staghom configuration. Conclusion The possibility of SFT should be considered when a single soft tissue mass with sharp border, inhomogeneous density is detected, especially with inhomogeneous enhancement maintaining in the venous phase.