Department of Pathology, Zuyderland Medical Centre, Dr. H. van der Hoffplein 1, 6162 BG Geleen, the Netherlands.
Department of Pathology, University Hospital of Copenhagen, Rigshospitalet, Frederik V's Vej 11, 2100 Copenhagen, Denmark.
Ann Diagn Pathol. 2020 Jun;46:151520. doi: 10.1016/j.anndiagpath.2020.151520. Epub 2020 Apr 5.
Microscopic colitis (MC) comprising lymphocytic colitis (LC), collagenous colitis (CC) and the incomplete forms of microscopic colitis (MCi) are frequent causes of chronic watery diarrhea. The diagnosis is based on specific histological features in colonic biopsies. Especially regarding MCi, the histological features may be subtle. The PRO-MC collaboration was established in 2016 with the aims to systematically describe the disease course and to validate the diagnostic criteria of MC. In the present study, we analysed pathologists' initial approach to diagnose MC. Five pathologists with expertise in gastro-intestinal pathology reviewed the first 10 cases enrolled in the PRO-MC registry in six of the participating centres. Despite considerable differences in strategies in biopsy sampling, in choice of stains and in minimum number of biopsies and segments required for diagnosing MC, inter-observer agreement between the participating centres and expert pathologists as well as among the latter was substantial. Disagreed cases most often related to difficulties in distinguishing between MC subgroups. We recommend that pathologists as well as clinicians reach consensus in their diagnostic approach to MC, which is a prerequisite to compare MC cohorts internationally and to facilitate clinical MC trials and follow-up studies.
显微镜结肠炎（MC）包括淋巴细胞性结肠炎（LC）、胶原性结肠炎（CC）和显微镜结肠炎的不完全形式（MCi），是慢性水样腹泻的常见原因。诊断基于结肠活检的特定组织学特征。特别是对于 MCi，组织学特征可能很细微。PRO-MC 协作组织成立于 2016 年，旨在系统描述疾病过程并验证 MC 的诊断标准。在本研究中，我们分析了病理学家诊断 MC 的初始方法。五位具有胃肠病理学专业知识的病理学家回顾了参与中心中的六个中心中 PRO-MC 注册中心纳入的前 10 例病例。尽管在活检采样策略、染色选择以及诊断 MC 所需的最小活检数量和节段数量方面存在相当大的差异，但参与中心之间以及专家病理学家之间的观察者间一致性以及病理学家之间的观察者间一致性都很高。有分歧的病例通常与区分 MC 亚组之间的困难有关。我们建议病理学家和临床医生在诊断 MC 的方法上达成共识，这是在国际上比较 MC 队列以及促进临床 MC 试验和随访研究的前提。
