Department of Pathology and Laboratory Medicine, London Health Sciences Centre, Western University, London, Ontario, Canada.
Division of Gastroenterology, Department of Medicine, London Health Sciences Centre, Western University, London, Ontario, Canada.
Clin Gastroenterol Hepatol. 2020 Aug;18(9):2003-2009. doi: 10.1016/j.cgh.2020.02.036. Epub 2020 Feb 25.
BACKGROUND & AIMS: Lymphocytic and collagenous colitis are types of microscopic colitis (MC) that commonly cause chronic watery diarrhea, but there are no macroscopic features of MC that can be detected during colonoscopy. Endoscopists therefore often collect multiple random colonic biopsies, potentially oversampling, increasing times of colonoscopy and slide review. We sought to identify sites from which biopsies could be taken and analyzed to identify patients with MC with a high level of sensitivity and determine the appropriate number of biopsies to take at these sites.
We performed a retrospective study using biopsies from 101 consecutive patients with MC (52 cases of collagenous colitis, 42 cases of lymphocytic colitis, 7 combined cases), without comorbidities, from 2017 through 2018. Slides were reviewed, and the proportion of biopsies that were diagnostic of MC were calculated at each biopsy site.
The proportions of biopsy fragments from each site of the colon found to be positive for MC were as follows: cecum, 90.0%; ascending colon, 96.9%; hepatic flexure, 77.8%; transverse colon, 95.7%; splenic flexure, 75.0%; descending colon, 85.0%; sigmoid colon, 90.9%; and rectum, 82.2%. For biopsies labeled random, 95.7% were positive for MC. When findings from ascending and descending colon biopsies were combined, 100% of MC cases were detected.
MC can be detected with certainty by analyzing biopsies from the ascending and descending colon. Fewer biopsies than were collected from our cases are sufficient for diagnosis. We propose a Western protocol (taking 2 biopsies from each of the ascending and descending colon) in evaluation of patients for MC.
淋巴细胞性和胶原性结肠炎是显微镜下结肠炎（MC）的两种类型，通常会引起慢性水样腹泻，但结肠镜检查期间无法检测到 MC 的任何宏观特征。因此，内镜医生通常会采集多个随机结肠活检，可能会过度采样，增加结肠镜检查和幻灯片审查的次数。我们旨在确定可以采集和分析活检的部位，以识别出具有高敏感性的 MC 患者，并确定在这些部位采集适当数量的活检。
我们进行了一项回顾性研究，纳入了 2017 年至 2018 年间的 101 例无合并症的 MC 患者（52 例胶原性结肠炎，42 例淋巴细胞性结肠炎，7 例混合型）的活检标本。我们对切片进行了回顾，并计算了每个活检部位诊断为 MC 的活检比例。
结肠各部位活检阳性片段中 MC 的比例如下：盲肠 90.0%；升结肠 96.9%；肝曲 77.8%；横结肠 95.7%；脾曲 75.0%；降结肠 85.0%；乙状结肠 90.9%；直肠 82.2%。标记为随机的活检中，95.7%为 MC 阳性。当将升结肠和降结肠的活检结果结合起来时，100%的 MC 病例都被检测到。
通过分析升结肠和降结肠的活检，可以确定 MC。比我们采集的病例数量更少的活检就足以诊断。我们建议采用西方方案（在升结肠和降结肠各取 2 个活检）来评估 MC 患者。
