结直肠神经鞘瘤和间质瘤的MSCT影像学特征分析

Analysis of MSCT imaging features of colorectal schwannomas and gastrointestinal stromal tumors

目的探讨有助于结直肠神经鞘瘤和间质瘤鉴别诊断的MSCT影像学特征。方法收集2007年1月~2017年4月笔者所在医院经病理确诊的16例结直肠神经鞘瘤和25例结直肠间质瘤患者MSCT影像资料,采用卡方检验或t检验分析二者影像学特征,ROC曲线分析阳性指标用于鉴别的效能。结果相对结直肠间质瘤而言,结直肠神经鞘瘤MSCT影像学特征表现为:直径小(2.5±1.3,t=3.850,P<0.001),结肠来源(75%vs 16%,Χ2=14.272,P<0.001),圆形(68.8%vs 36%,Χ~2=4.188,P=0.041),边缘光滑(68.8%vs 32%,Χ~2=5.299,P=0.021),均质(93.8%vs 48%,Χ~2=9.081,P=0.003),较少发生囊变(12.5%vs 60%,Χ~2=9.069,P=0.003)、坏死(6.25%vs 44%,Χ~2=6.716,P=0.010),轻中度强化(87.5%vs 52%,Χ~2=5.468,P=0.019),区域淋巴结肿大(31.3%vs 0,Χ~2=8.898,P=0.003)。两者在性别、年龄、肿瘤生长方式、有无钙化、表面溃疡、远处转移方面,差异无统计学意义(P>0.05)。ROC曲线分析发现CT测量的肿瘤最大径4.4cm为最佳界值,鉴别结直肠神经鞘瘤和间质瘤的敏感性和特异性分别为88.0%(22/25)和87.5%(14/16),曲线下面积(AUC)=0.915。结论结直肠神经鞘瘤MSCT特征表现为结肠来源体积较小的肿瘤,边缘光滑,均质,较少发生囊变和坏死,可伴区域淋巴结肿大。

Objective To investigate the MSCT imaging features to assist in differentiating colorectal schwannomas from gastrointestinal stromal tumors. Methods The MSCT imaging data of 16 colorectal schwannomas and 25 gastrointestinal stromal tumors（ GISTs） diagnosed by pathology from January 2007 to April 2017 in our hospital were retrospectively analyzed. The chi square test or t test was used to analyze the significant variables of MSCT features. The receiver operating characteristic（ ROC）curve analysis was used to assess the ability of the positive indicators. Results Compared with colorectal GISTs,the MSCT imaging features of colorectal schwannoma were more frequently demonstrated smaller size（ 2. 5 ± 1. 3,t = 3. 850,P〈0. 001）,derived from colon（ 75% vs 16%,Χ^2= 14. 272,P〈0. 001）,round contouring（ 68. 8% vs 36%,Χ^2= 4. 188,P = 0. 041）,smooth margin（ 68. 8% vs 32%,Χ^2= 5. 299,P = 0. 021）,homogeneous（ 93. 8% vs 48%,Χ^2= 9. 081,P = 0. 003）,rare cystic changes（ 12. 5% vs 60%,Χ^2= 9. 069,P = 0. 003） and necrosis（ 6. 25% vs 44%,Χ^2= 6. 716,P = 0. 010）,light to moderate enhancement degree（ 87. 5% vs 52%,Χ^2= 5. 468,P = 0. 019）,enlarged regional lymph nodes（ 31. 3% vs 0,Χ^2=8. 898,P = 0. 003）. There was no significant difference in gender,age,tumor growth pattern,calcification,surface ulcer and distant metastasis（ P〈0. 05）. ROC analysis indicated that the optimal cut-off point for the maximum diameter of the tumor measured by MSCT in distinguishing GISTs from schwannomas was 4. 4 cm. The sensitivity and specificity were 88%（ 22/25） and87. 5%（ 14/16） respectively,the area under the curve（ AUC） was 0. 915. Conclusion The MSCT imaging features of colorectal schwannomas were mainly colonic origin,smaller size,smooth margin,homogeneous,rare cystic changes and necrosis,and can accompany with enlarged regional lymph nodes.