血吸虫肠病合并结直肠癌的计算机X线断层扫描影像学表现

Multi-slice spiral computerized tomography findings of colorectal cancer with chronic schistosomiasis

目的 回顾性分析血吸虫肠病合并结直肠癌的CT表现,旨在提高对该病诊断的准确性.方法 2007年1月至2012年12月同济大学附属同济医院和昆山市中医院收治的80例经病理学检查证实为血吸虫肠病合并结直肠癌患者,均行腹部CT平扫十增强扫描,由两名放射科医师采用盲法阅片,对病灶部位、形态、大小,钙化特点及强化方式,有无转移进行评估;同时收集同一地区非血吸虫结直肠癌患者20例作为对照.结果 80例血吸虫肠病合并结直肠癌患者的肿瘤以降结肠、乙状结肠和直肠为主,表现为管壁不规则增厚,伴软组织团块,累及肠管长度为（21.35±4.50） cm;其中单发病灶68例（85.0％）,多发病灶12例（15.0％）,表现为多节段肠管受累;肿瘤组织均可见不同形态的钙化灶,钙化发生比例为100.0％,主要表现为线状、斑点状及小斑片状钙化影,其中59例（73.8％）钙化边缘模糊,21例（26.2％）钙化边缘较清晰;增强早期68例（85.0％）病灶明显强化,均匀强化45例（56.2％）,不均匀强化23例（28.8％）,增强晚期73例（91.2％）持续强化,坏死少见;仅2例（2.5％）伴发肝脏转移瘤,均无淋巴结转移.20例非血吸虫结直肠癌患者肿瘤均为单发病灶（100.0％）,表现为肠壁不规则增厚,伴局部溃疡形成,累及肠管长度为（6.90±3.40） cm;肿瘤组织内均未见钙化影;均表现为增强早期病灶明显不均匀强化,可见低密度坏死区存在,增强晚期不同程度降低;4例（20.0％）伴发肝脏转移瘤.与非血吸虫结直肠癌患者比较,血吸虫肠病合并结直肠癌患者多发病灶的比例较高（x2=100,P=0.000）,病变管壁长度较长（t=45.506,P=0.000）,钙化灶发生比例较高（x2=100,P=0.000）,增强早期病灶明显不均匀强化比例较低（x2 =88,P=0.000）,晚期病灶持续强化比例较高（x2=100,P=0.000）;肝脏转移发生比例较低（x2 =8.688,P=0.014）.结论 血吸虫肠病合并结直肠癌在CT上特征性表现为瘤组织内不同形态钙化影,钙化边缘模糊,并累及多节段肠管;血道转移及淋巴道转移均少见.

Objective To retrospectively analyze computerized tomography （CT） imaging features of colorectal cancer with chronic schistosomiasis in order to improve the diagnostic accuracy.Methods Eighty patients whose diagnosis was pathologically confirmed as colorectal cancer with schistosomiasis were collected from Tongji Hospital and Kunshan Chinese Medicine Hospital from January 2007 to December 2012.All the patients underwent abdominal plain CT and contrast-enhanced CT scan.The lesion location,morphology,size,calcification features,enhancement patterns and cancer metastasis were evaluated and compared by two radiologists who were blind to the diagnosis.Twenty colorectal cancer cases without schistosomiasis from the same area were also collected as controls.Results CT imaging showed that the tumors all occurred in the colon and rectum in 80 patients,mainly in colon descendens,colon sigmoideum and rectum.The lesion was characterized by irregular bowel wall thickening with soft tissue masses,and the average length of impaired intestine was （21.35 ± 4.50） cm.The lesions were solitary in 68 cases （85.0%） and were multifocal in 12 cases （15.0%）.Linear,spotty and small patchy calcifications were seen in all the patients,with margins unclear in 59 patients （73.8%） and margins clear in 21 patients （26.2%）.Early phase enhancement was seen in 68 cases （85.0%）,of which 45 cases （56.2%） had homogenous enhancement and 23 cases （28.8%） had heterogeneous enhancement.Late phase enhancement was seen in 73 cases （91.2%） and necrosis was hardly seen.Only two cases （2.5%） had liver metastasis without lymphatic metastasis.All the 20 colorectal cancer cases without schistosomiasis presented with single lesion,which was characterized by irregular bowel wall thickening and local ulcer.The average length of impaired intestine was （6.90±3.40） cm.No calcification was seen in these lesions.All cases had early phase lesion with remarkable heterogeneous enhancement with low density necrotic area.The late phase enhancement was decreased.Four cases （20.0%） had liver metastasis.Compared to cases without schistosomiasis,cases with schistosomiasis tended to have multifocal （x2=100,P=0.000） and longer lesion （t=45.506,P=0.000）,and more calcification （x2=100,P=0.000）.The early phase heterogeneous enhancement was less frequent （x2 =88,P=0.000） and late phase enhancement was more frequent （x2=100,P=0.000）.The liver metastasis rate was significantly lower （x2 =8.688,P =0.014）.Conclusions The CT imaging of colorectal cancer with schistosomiasis is characterized by calcifications inside the tumor with obscured margins and multiple intestinal segments involvement.Hematogenous metastasis and lymphatic metastasis are rarely seen.