IMAGES IN CLINICAL MEDICINE

Colon Cutoff Sign

Po-Yi Chen, M.D.

N Engl J Med 2018; 378:1621

DOI: 10.1056/NEJMicm1714270

A 74-year-old woman presented to the emergency department with a 3-day history of lower abdominal pain, nausea, and vomiting. She had been unable to pass any stool for 1 week and reported having had small-caliber stool during the previous 6 months. On physical examination, bowel sounds were reduced, and the patient had periumbilical tenderness. Laboratory studies revealed normocytic anemia with a hemoglobin level of 9.6 g per deciliter (reference range, 12.3 to 15.3). A plain-film radiograph of the abdomen showed marked dilatation of bowel loops and abrupt termination of gas within the descending colon, referred to as a colon cutoff sign (Panel A, arrow). Computed tomography of the abdomen revealed segmental wall thickening of the descending colon (Panel B). Colonoscopy revealed a circumferential ulcerative lesion in the descending colon, and the results of pathological testing were consistent with adenocarcinoma of the colon. In this patient, the colon cutoff sign was caused by mechanical narrowing due to colon cancer. The colon cutoff sign is classically described in association with acute pancreatitis, when inflammation causes spasm or narrowing at the splenic flexure. The patient underwent hemicolectomy on the left side and received adjuvant chemotherapy. At follow-up 4 months after surgery, she had no evidence of local disease recurrence or distant metastases.

一名74岁女性患者因下腹部疼痛、恶心呕吐3天到急诊科就诊。患者未排便已有一周，且主诉过去6个月间大便变细。体格检查发现，肠鸣音减弱，脐周压痛。实验室检查显示正细胞性贫血，血红蛋白9.6 g/dL（正常值范围12.3-15.3）。腹平片显示肠襻明显扩张，在降结肠部位积气突然中断，这称之为结肠中断征（图A，箭头）。腹部CT显示降结肠节段性肠壁增厚（图B）。结肠镜检查发现降结肠内有环状溃疡病变，病理检查结果符合结肠腺癌。在这名患者，结肠中断征系结肠癌导致的机械性狭窄引起。典型情况下，结肠中断征常伴随急性胰腺炎出现，此时炎症反应导致结肠脾区痉挛或狭窄。患者接受了左半结肠切除术及辅助化疗。手术后4个月随访时，患者没有肿瘤局部复发或远处转移的表现。