腹膜后间隙孤立性纤维性肿瘤的CT表现与病理对照

The Correlation Between CT Findings and Pathology in Retroperitoneal Solitary Fibrous Tumor

目的探讨腹膜后间隙孤立性纤维性肿瘤(SFT)的CT表现及病理特征。方法回顾性分析7例经手术病理证实的腹膜后间隙SFT患者的CT表现及病理,包括良性SFT 3例,恶性SFT 3例,脂肪瘤型SFT 1例。男5例,女2例,平均年龄54.7岁。6例行平扫与增强,1例平扫。结果 (1)7例中,盆部腹膜外间隙4例,腹腔腹膜后间隙3例。(2)CT表现为肿块境界清楚,内部密度欠均匀,见多发灶性或不规则形稍低密度区;增强动脉期见迂曲扩张血管影,实性部分不均匀斑驳样强化,实质期强化较均匀,囊变坏死区无强化。恶性SFT 3例均伴有大面积出血、坏死。(3)病理表现为肿瘤细胞由梭形细胞组成,细胞间富有束状胶原纤维和分支状薄壁血管。免疫组织化学除1例恶性SFT的CD34及CD99阴性表达外,其余病例CD34、bcl-2、CD99、Vimentin均阳性表达。结论腹膜后间隙SFT的CT表现有一定特征但缺乏特异性,最终诊断需病理及免疫组织化学证实。

Objective To investigate the CT findings and pathological features of retroperitoneal solitary fibrous tumor（SFT）.Methods The CT findings of 7 patients（5 males and 2 females,mean age 54.7 years.） with retroperitoneal solitary fibrous tumor confirmed by surgical pathology were retrospectively analyzed and compared with pathology,including 3 cases with benign SFT,3 cases with malignant SFT,1 case with lipomatosis SFT.All patients received plain CT scanning,6 of them received enhanced CT scanning.Results（1）Among 7 cases,the lesions of the 4 cases located at pelvic extraperitoneal space and the others located at abdominal retroperitoneal space.（2）On unenhanced CT,the lesions appeared as well circumscribed heterogeneous soft tissue masses with focal areas of low attenuation.On enhanced CT,the lesions showed marked,heterogeneous enhancement with dilated vessels in the arterial phase and persistent and prolonged enhancement in the parenchyma phase.Areas of necrosis or cystic did not enhance.The lesions of malignant SFT were accompanied with extensive hemorrhage and necrosis.（3）On histopathological results,the tumors were composed of spindle cells with abundant collagen fibers and thin walled branching vessels,on immunohistochemical results,except one case with malignant SFT was negative for CD34 and CD99,all other cases were positive for CD34,bcl 2,CD99 and vimentin.Conclusion The CT appearance of retroperitoneal solitary fibrous tumor has some characteristics without specific features.The final diagnosis is still depended on pathology and immunohistochemistry.