MSCT在鉴别≤3cm的低、高风险胸腺瘤及胸腺癌中的价值

目的 探讨多层螺旋CT(MSCT)对最大径≤3 cm的胸腺上皮肿瘤(TET)诊断价值.方法 回顾性分析56例经病理证实的最大径≤3 cm的TET病例的病理、影像学资料,根据WHO 2004标准进行组织学分型,将病例分为低风险胸腺瘤组(A/AB/B1型)、高风险胸腺瘤组(B2/B3型)、胸腺癌组(C型),分析各组TET的CT征象,包括病灶的形状、边缘是否光滑、是否伴有棘状突起、是否伴有瘤周小结节、强化程度、胸膜侵犯征象、周围脂肪间隙等.各类型间比较采用χ2检验,样本量过小时,采用Fisher精确试验.结果 低风险胸腺瘤(27例)较高风险胸腺瘤(23例)及胸腺癌(6例)更常表现为规则的类圆形的形态(χ2=73,P<0.001;χ2=116,P<0.001),纵隔-肺界面更易呈膨隆状(χ2=3.41,P=0.046;χ2=7.39,P=0.01);高风险胸腺瘤、胸腺癌较低风险胸腺瘤更常见边缘模糊、棘状突起、胸膜侵犯等征象(P<0.001);胸腺癌较高风险胸腺瘤更常见边缘模糊、棘状突起、胸膜侵犯等征象(χ2=11.5,P=0.009);B2型胸腺瘤与胸腺癌之间的差异有显著性意义(χ2=31.52,P<0.001),然而B3型胸腺瘤与胸腺癌之间无统计学差异(χ2=6.96,P=0.07).结论 MSCT可准确显示病灶的形态、边缘、瘤周情况、强化程度及胸膜侵犯情况,在一定程度上可预测胸腺瘤的组织学分型,可为术前诊断及预后评估提供依据.

The value of MSCT in differentiating low-or high-risk thymomas and thymic carcinomas with maximum diameter equal or less than 3 cm

Objective To evaluate the diagnostic value of MSCT in the differentiation of thymic epithelial tumours (TET)with the maximum diameter equal or less than 3 cm.Methods A retrospective analysis of pathological and imaging data of 56 patients with pathologically confirmed TET with the maximum diameter equal or less than 3 cm was performed.According to the 2004 WHO classification,56 TETs were classified as low-risk thymomas(types A/AB/B1),high-risk thymomas (types B2/B3)and thymic carcinomas (type C).The CT manifestations of TET in each group,including shape of tumor,tumor edge (smooth or spiculate protuberance), presence of small nodule around tumor,enhancement degree,pleura invasion and fat space around tumor,were analyzed retrospectively.The differences in the CT manifestations among three types were compared using chi-square test.If the sample number was too small, Fisher 's exact test was used.Results Compared with high-risk thymomas (23 cases)and thymic carcinomas (6 cases),regular round shape was more often observed in low-risk thymomas (27 cases)(χ2 =73,P <0.001;χ2 =116,P <0.001)and the mediastinum-lung interface was more likely to bulge (χ2 = 3.41,P =0.046;χ2 =7.39,P =0.01).Blurred edge,spiculate protuberance and pleural invasion and so on were significantly more common in high-risk thymomas and thymic carcinomas (P <0.001)and they were the most common in thymic carcinomas (χ2 =11.5,P =0.009).There was a significant difference between type B2 thymomas and thymic carcinomas (χ2 =31.52, P <0.001),however there was no significant difference between type B3 thymomas and thymic carcinomas (χ2 =6.96,P =0.07). Conclusion MSCT can accurately show the shape of tumor,tumor edge,presence of small nodule around tumor,enhancement degree,pleura invasion,which can predict the histologic type of thymomas and also can provide information for preoperative diagnosis and prognosis evaluation.