胸膜外孤立性纤维瘤的影像学诊断及病理特征

目的 分析胸膜外孤立性纤维瘤(SFT)的CT、MR表现及病理特征,提高对本病的认识及影像诊断水平.方法 回顾性分析经病理证实的32例胸膜外SFT的临床资料、CT、 MR表现及其病理免疫组化特征.结果 32例SFT发生于头颅5例,眼眶3例,鼻窦1例,支气管1例,胃 2例,胰腺1例,肾脏3例,后腹膜3例,盆腔4例,软组织6例,椎旁3例.恶性6例,交界性8例,良性18例.发生于腹盆腔肿瘤体积较大,平均直径13.6 cm;其余部位肿瘤体积较小,平均4.2 cm.大部分肿瘤表现为边界清楚,边缘光整或分叶状软组织密度肿块,部分见坏死,囊变及钙化少见,MR平扫多表现为等长T1等长T2信号,增强后部分肿块周围及内部可见多发迂曲血管影,肿块动脉期实体部分强化程度较轻,而静脉期进一步强化明显,一般呈不均匀的轻中度至明显强化.此外,部分肿瘤可见"阴-阳"信号改变.免疫组化示:CD34阳性率100%,CD99阳性率68.8%,Bcl-2阳性率62.5%,Vimentin阳性率46.9%,Ki-67>5%阳性率43.8%.结论 胸膜外SFT具有一定特征性的影像学表现,免疫组化CD34阳性有重要诊断意义.

Extra-pleural solitary fibrous tumor: imaging and histopathologic features

Objective To analyze the imaging and histopathologic features of extra-plural solitary fibrous tumor (SFT) and to improve the diagnose diagnostic ability.Methods The images and pathologic features of 32 SFT cases confirmed by pathology were retrospectively reviewed.Results Of 32 SFT cases, there were 5 cases in the head, 3 cases in the orbit, 1 case in the nasal sinuses, 1 case in the bronchus, 2 cases in the stomach,1 case in the pancreas, 3 cases in the kidney, 3 cases in the retroperitoneum, 4 cases in the pelvic cavity, 6 cases in the soft tissues, 3 cases near the vertebra.6 cases were malignant,8 cases were borderline,18 cases were benign.The tumors located in abdominal and pelvic tumors were larger,the average diameter of the tumors was 13.6 cm.The volumes of the other tumors were smaller, the average diameter was 4.2 cm.The majority of the tumors showed clear boundary, smooth edge or lobulated soft tissue mass, partial necrosis, rare cystic degeneration and calcification.MR images showed hypo to isointensity on T1WI and hyper to isointensity on T2WI.After enhanced enhancement, multiple small circuitous vessels could be found in or around the mass.The tumor showed slightly enhanced in the arterial phase and moderately to obviously heterogeneously enhancement in the venous phase.In addition, part of the tumors can could be seen "positive-negative" signal changes.The positive expression rate of immunohistochemical indexes were: CD34 100%, CD99 68.8%, Bcl-2 62.5%, Vimentin 46.9%, Ki-67>5% 43.8% respectively.