胸膜外孤立性纤维瘤的影像表现与病理对照研究

Comparative study of imaging manifestations and pathology of extrapleural solitary fibrous tumor

目的:分析总结胸膜外孤立性纤维瘤的影像表现及病理基础,提高诊断准确性。方法:回顾性分析30例经病理证实的胸膜外孤立性纤维瘤的CT、MRI表现。5例患者仅进行了CT检查,19例患者仅进行了MR检查,6例同时行CT和MR检查。结果:30例患者均为单发病灶,其中13例位于中枢神经系统,7例位于头颈部、6例位于腹盆腔、1例位于食管、1例位于乳腺、1例位于腹股沟、1例位于耻骨。病灶多呈类圆形或长圆形,部分病例可见分叶或形态不规则。CT平扫颅内病灶呈不均匀等低密度或均匀稍高密度,其余病灶CT平扫呈均匀软组织密度。头颈部病灶T1WI呈较均匀等低信号,其余病灶T1WI呈欠均匀等低信号,T2WI信号混杂,可见等、低、高信号;15例病灶边缘或病灶内可见血管流空信号。增强扫描颅内病灶呈明显不均匀强化,其余病灶呈中度到明显不均匀强化,腹盆腔病灶可见渐进性强化;T2低信号区可见强化,坏死囊变区未见强化。免疫组化可见CD34、STAT-6、VIM、CD99、Bcl-2阳性。结论:胸膜外孤立性纤维瘤分布广泛,病理基础决定其信号及强化特征,T2WI见条片状、结片状低信号,增强扫描T2WI低信号区强化,有一定特征性。CD34、STAT-6相结合有利于提高SFT诊断的特异度和敏感度。

Objective:To analyze and summarize the imaging manifestations and pathological basis of the extrapleural solitary fibrous tumor so as to improve the diagnostic accuracy.Method:The CT and MRI findings of 30 patients with pathologically proved extrapleural solitary fibrous tumors were retrospectively analyzed.Five patients only underwent CT examinations,19 patients only underwent MR examinations,and 6 patients underwent CT and MR examinations.Results:All the 30 cases had a single lesion,including 13 in the central nervous system,7 in the head and neck,6 in the abdominal and pelvic cavity,1 in the esophagus,1 in the breast,1 in the groin,and 1 in the pubis.Most of the lesions were round or oblong,and lobulated or irregular in some cases.On plain CT scan,the intracranial lesions showed heterogeneous low density or even slightly high density,while other lesions showed homogeneous soft tissue density.The head and neck lesions showed homogeneous iso-or hypointensity on T1WI,and the remaining lesions showed homogeneous iso-or hypointensity.T2WI signals were heterogeneous and showed hyper-,iso-,or hypointensity.Vascular flow void signal could be seen on the edges or within the lesions in 15 cases.On contrast-enhanced MRI,intracranial lesions presented markedly heterogeneous enhancement,and other lesions showed moderate to obvious heterogeneous enhancement.Progressive enhancement was seen in abdominal and pelvic lesions;enhancement was seen in the T2 low-signal area,and no enhancement was seen in the necrotic area.Immunohistochemical staining showed that CD34,STAT-6,VIM,CD99,Bcl-2 were positive.Conclusion:Extrapleural solitary fibrous tumor is widely distributed,and it's signal and enhancement characteristics are determined by its pathological basis.Strip like and patch-like low signal can be seen on T2WI,and enhancement of the T2 low-signal area has specific characteristics.The combination of CD34 and STAT-6 can improve the specificity and sensitivity of solitary fibrous tumor diagnosis.