胸内孤立性纤维瘤3例报告并文献复习

Intrathoracic Solitary Fibrous Tumor: A Report of 3 Cases and Review of the Literature

目的探讨胸内孤立性纤维瘤(solitary fibrous tumor,SFT)的影像学表现,提高对该病的诊断和鉴别诊断水平。资料与方法回顾性分析3例经手术病理证实的胸内SFT的临床、影像学及病理资料。3例均行螺旋CT平扫与增强扫描,其中2例行多平面重组(multi-planar reformatting,MPR),1例行MRI平扫;结合文献探讨胸内SFT的影像学表现。结果 3例胸内SFT分别位于肺内、斜裂胸膜、后胸壁脏层胸膜,肿块均为孤立肿块。1例左下叶背段外周肿块CT平扫为界限清楚软组织肿块,增强扫描动脉期肿块内见"簇"状、"线"状强化小血管影,延时扫描肿块呈非均匀强化,部分实性成分呈渐进性强化;MR T1WI上肿块呈稍短T1信号,T2WI上呈"地图"样高低混杂信号,以短T2信号为主;1例斜裂肿块平扫表现为"卵圆"形边缘光滑均质软组织密度肿块,增强扫描呈中度均匀强化;1例后胸壁脏层胸膜肿块CT平扫为非均质肿块,增强后肿块呈轻度类环状强化,内部见大片非强化坏死区,邻近见"贴边血管征"。3例均未见肺门和纵隔淋巴结肿大,手术病理结果示肿块界限清楚,有包膜或假包膜。镜下肿瘤细胞为长梭形,细胞排列成"束"状、"漩涡"状或"不规则"状,细胞密集区与疏松区交替出现,可见粗大的"瘢痕"样玻璃变性的胶原纤维相间,部分视野可见血管外皮瘤样结构,1例左下叶背段病变示陷入的细支气管及肺泡上皮。免疫组织化学检查:CD34或CD99、癌基因(Bcl-2)、波形蛋白(Vimentin)均呈强阳性。结论胸内SFT少见,其影像表现具有相对特征性,确诊需依靠病理组织学及免疫组织化学检查。

Objective To evaluate the imaging findings of intrathoracic solitary fibrous tumor（SFT） in order to improve its diagnosis and differential diagnosis.Materials and Methods The clinical,imaging and pathology findings of 3 patients pathologically proved SFT were retrospectively analyzed.All of 3 cases underwent spiral CT plain and contrast enhanced scans,2 cases underwent multi-planar reformatting（MPR）,1 case underwent MR plain respectively,and the literatures were combined to evaluate the imaging findings of intrathoracic SFT.Results One of the tumors located in the lung,and one at oblique fissure and one at visceral pleura of the posterior chest wall respectively.The tumor was a single mass.One was a well defined mass with homogeneous density in the edge of the left lower lobe on plain CT scan.After contrast enhancement,enhanced blood vessels were seen inside the tumor in the arterial phase,inhomogeneous enhancement was seen in delay scanning,and progressive strengthening was seen in the solid part of the tumor,most of the mass showed the short T2 signal on MRI.Another showed a ovoid mass with homogeneous soft tissue density and smooth edge,the mass was moderate strengthening homogeneously.The tumor in the visceral pleura of the posterior chest wall was a mass with inhomogeneous density,and was mild strengthening with ring shape,there was a large necrotic area in the mass.There was no enlargement of mediastinal,hilar lymph nodes in all of 3 cases.Gross and histological findings by postoperative pathology showed a well circumscribed mass with capsule or pseduocapsule.Under microscope the tumor cells were spindle,the spindle cells were bundle,spiral or irregular distribution,mixed with abundant collagen fibers.Hypercellular and hypocellular sclerotic foci showed up alternatively,there was increased vasculatue with hemangiopericytoma like pattern and with entrapped bronchiolar and alveolar epithelium in one of the tumors.The immunohistochemical examination of CD34 or CD99,Bcl 2 and Vimentin were strong positivity.Conclusion Intrathoracic SFT is rare.There are some relatively specific imaging findings,however its diagnosis is depend on pathology and immunohistochemistry.