结直肠同时性多原发癌的MSCT漏诊原因分析

Missed diagnosis analysis of synchronous colorectal carcinoma on MSCT

目的:分析结直肠同时性多原发癌中的MSCT漏诊原因,以减少漏诊。方法:回顾性分析经病理证实的17例结直肠同时性多原发癌患者的病例资料,观察、记录患者的一般资料、结肠镜、病理、肿瘤长径、发病部位、MSCT表现、漏诊及其原因;按是否漏诊分为漏诊组与未漏诊组,比较两组间的一般资料、肿瘤漏诊率、肿瘤大小以及MSCT与结肠镜检查的诊断符合率。结果:17例患者手术证实均为双原发癌,其分布为:右-右半结肠组3例,右-左半结肠组1例,右-直乙状结肠组5例,左-直乙状结肠组2例,直乙状结肠组6例;术前MSCT检查漏诊肿瘤10处(29.4%,10/34),其中近端肿瘤6处(升结肠、乙状结肠各2处,结肠肝区、横结肠各1处),远端肿瘤4处(横结肠2处,结肠脾曲、乙状结肠各1处),漏诊原因包括:技术因素、肿瘤形态、体积、病理因素及肠套叠。结肠镜检查漏诊1处(2.9%,1/34),原因为远端肿瘤致肠腔狭窄,肠镜探头无法通过。以肿瘤病灶为分析对象,肿瘤病理对漏诊发生的影响有统计学意义,黏液腺癌和腺瘤恶变的漏诊率高于腺癌,差异有统计学意义(P值均<0.001)。CT漏诊肿瘤的长径为2.5 cm(1.5,3.0),未漏诊肿瘤的长径为4.0 cm(2.8,6.0),差异有统计学意义(Z=2.041,P=0.041)。CT诊断符合率为70.6%(24/34),肠镜诊断符合率为97.1%(33/34),差异有统计学意义(P=0.004)。将10处漏诊按出现频次进行排序,最主要的原因为技术因素、肿瘤形态。结论:结直肠同时性多原发癌并不少见,诊断者应考虑结直肠同时性多原发癌的可能,完善CT检查技术,提高对不典型肿瘤及病理改变的认识。

Objective:To investigate the causes of missed diagnosis of synchronous colorectal carcinoma(SCC)on MSCT.Methods:The clinical and imaging data of 17 patients with SCC confirmed by pathology were retrospectively analyzed.The general information,colonoscopic and pathological results,tumor longitudinal size,lesions'location features of MSCT and causes of missed diagnosis were recorded.All patients were divided into missed diagnosis and non-missed diagnosis groups.The general information,missed diagnostic rate,tumor size,and diagnostic coincidence rate between MSCT and colonoscopy were compared between two groups.Results:Totally 17 patients were surgically confirmed to be double SCC.There were 3 cases in the right-right hemi-colon group,1 case in the right-left hemi-colon group,5 cases in the right hemi-colon and the rectosigmoid colon group,2 cases in the left hemi-colon and rectosigmoid colon group,6 cases in the rectosigmoid colon group.There were 10 tumors(29.4%,10/34)missed in the preoperative MSCT examination,including 6 proximal tumors(2 in ascending colon,2 in the sigmoid colon,1 in the hepatic colon,and 1 in the transverse colon),and 4 distal tumors(2 in the transverse colon,1 in splenic curvature and 1 in sigmoid colon).The reasons of missed diagnosis included technical factor,cancer shape,pathological factors,tumor volume,and intussusception.One tumor was missed on colonoscopy because the colonoscopy probe could not pass the intestinal stenosis caused by distal cancer.The tumors'pathological type on the occurrence of missed diagnosis was statistically significant.The misdiagnosis rate of mucinous carcinomas and adenoma malignancy was higher than that of adenocarcinoma(P<0.001).There were statistically significant(Z=2.041,P=0.041)between the size of the misdiagnosed tumor(2.5cm)and diagnosed tumor(4.0cm).There were statistically significant(P=0.004)between the positive rate of CT(70.6%)and colonoscopy(97.1%).According to the occurrence frequency,the most important reasons for missed diagnosis were technical factors,cancer shape.Conclusions:Synchronous colorectal carcinoma is not uncommon.We should pay attention to the possibility of synchronous colorectal carcinoma and improve the understanding of atypical tumors and pathological changes by perfecting the CT examination technology.