头颈部孤立性纤维瘤的影像表现

Imaging Findings of Solitary Fibrous Tumor in the Head and Neck Region

目的探讨头颈部孤立性纤维瘤（SFT）的影像学特征,提高对本病罕见部位的认识。方法回顾性分析经手术病理证实的8例头颈部SFT的影像表现。术前行CT检查者5例,4例行增强扫描;行MRI检查者4例,均行增强扫描。其中1例同时行MRI与CT检查。结果 （1）8例头颈部SFT中,海绵窦区-鞍旁1例,甲状腺1例,椎管内2例,翼腭窝2例,颌下1例,颈部1例。肿瘤直径1.4~6.8 cm,呈圆形或卵圆形7例,浅分叶1例。边界清楚8例。（2）5例CT平扫密度均匀,未见囊变、出血、坏死及钙化。1例周围骨质破坏。（3）MRI平扫T_1WI 4例肿瘤主体呈等信号,1例见少许出血灶。3例肿瘤T_2WI呈等低信号,1例高低混杂信号,1例等信号。1例少许囊变坏死灶。1例周围少许水肿。1例DWI高低混杂信号。（4）增强扫描,3例病灶动脉期不均匀强化,5例均匀强化,4例见迂曲管影,T_2WI低信号区也呈明显强化;静脉期渐进性均匀强化。结论头颈部SFT影像表现具有一定的特点,T2WI信号更为典型,当肿瘤T_2WI信号混杂,与DWI信号相对应,且T_2WI低信号区明显强化,有利于诊断SFT。

Objective To discuss the imaging characteristics of solitary fibrous tumor（ SFT） in the head and neck region and improve the understanding of this disease in rare locations. Methods The imaging findings of 8 cases with SFT in the head and neck region proven by surgery and pathology were analyzed retrospectively. Preoperatively,5 patients underwent CT examinations,4 patients underwent enhancement scan; MRI scans were performed in 4 cases,2 of the 4 cases underwent enhancement scan. Among them,both CT and MRI scans were performed in 1 case. Results（ 1） SFT were located in cavernous sinus-parasellar region（ 1 /8）,thyroid（ 1 /8）,spinal canal（ 2 /8）,pterygopalatine fossa（ 2 /8）,submandibular region（ 1 /8）,neck（ 1 /8）. The tumor size was 1. 4- 6. 8 cm. Among the tumors,7 were round or oval in shape and 1 tumor was lobulated. Eight lesions had a well-defined boundary.（ 2） Five cases performed by CT scan showed homogeneous density with no cystic degeneration,hemorrhage,necrosis and calcification. One case showed adjacent bone destruction.（ 3） On MR Scan,4 cases showed an isointense signal on T_1WI and hemorrhagic focus was detected in 1 case.Three cases showed iso- and hypo-intensity on T_2WI,1 case showed mixed hyperintense and hypointense signals,1 case showed an isointense signal,cystic degeneration and necrosis were seen in 1bcase. One case showed a little peritumoral edema. One case showed hyperintense and hypointense signals on DWI.（ 4） In the arterial phase of the enhanced scan,3tumors showed inhomogeneous enhancement,homogeneous enhancement was displayed in 5 cases and tortuous vessels were seen in 4 cases. Obvious enhancement was seen in low T_2 signal regions. Progressive enhancement was seen in the venous phase. Conclusion SFT in the head and neck regions has some specific imaging features. T_2WI signal intensity is more typical. It was helpful to the diagnosis of SFT while T_2WI showed a mixed signal that corresponded to DWI signal intensity,and areas of hypointensity on T_2WI enhanced strongly.