Singapore General Hospital and National University of Singapore, Singapore.
Pathology. 2010 Feb;42(2):131-7. doi: 10.3109/00313020903494979.
Endoscopic biopsy diagnosis of Crohn's disease (CD) is problematic due to lack of specific microscopic features and patchy involvement. There is no documentation of the pattern and severity of microscopic features of CD at initial presentation in adults or children. We aimed to assess the initial mucosal biopsy features of CD in adults and to identify any specific features to confirm the diagnosis.
Thirty sets of initial, adult endoscopic biopsies suspected to be CD with subsequent resections, repeat biopsies with long-term follow-up, and/or other confirmatory laboratory results were analysed by three gastrointestinal pathologists, blinded for the final diagnosis for mucosal architectural changes, epithelial abnormalities, chronic and active inflammation and changes of muscularis mucosae and submucosa. There were 25 cases of CD and five cases of non-CD for comparison (3 tuberculosis and 2 right-sided diverticular disease and associated colitis). Cases confirmed as ulcerative colitis were excluded, as diagnostic challenges are already well established.
The majority of initial biopsies (96%) of CD were abnormal with active chronic ileocolitis with a very high proportion (80%) showing the classic combination of abnormal mucosal architecture, epithelial abnormalities and active chronic inflammation. The most sensitive feature was lamina proprial chronic inflammation (sensitivity 92.7%). Sensitivity for other features was as follows: active inflammation 87.8%, basal plasmacytosis 82.1%, architectural changes 80.5% and epithelial abnormalities 70.7%. Abnormalities were found in 94% of ileal and 76% of colonic biopsies. No feature was specific as all tuberculosis and diverticular disease cases showed the classic combination. Granulomata were seen in 10 of 41 CD, in all five tuberculosis and in no diverticular disease biopsies. Small, tight, well defined granulomata characterised CD over large coalesced ganulomata of tuberculosis. Paneth cell and pseudopyloric metaplasia was seen only in CD (2/25).
Initial endoscopic biopsies of adult CD are significantly abnormal and a majority shows active chronic ileocolitis. The features are sufficiently important to suspect CD at initial presentation in the appropriate clinical setting. Tuberculosis and diverticular disease associated colitis are two important mimics to consider in addition to ulcerative colitis.
由于缺乏特异性的显微镜特征和斑块性累及，克罗恩病（CD）的内镜活检诊断存在问题。目前尚无关于成人或儿童初次就诊时 CD 的微观特征模式和严重程度的相关文献记录。我们旨在评估成人 CD 的初次黏膜活检特征，并确定任何有助于确诊的特定特征。
对 30 套经内镜活检怀疑为 CD 的成人标本进行分析，这些标本均有后续的切除术、重复活检和/或其他确证性实验室结果，由 3 位胃肠病理学家进行分析，他们对最终诊断为黏膜结构改变、上皮异常、慢性和活动性炎症以及黏膜固有层和黏膜下层改变的盲法评估。其中 25 例为 CD，5 例为非 CD（3 例为结核病，2 例为右侧憩室病伴相关结肠炎）。排除了确诊为溃疡性结肠炎的病例，因为其诊断挑战已经得到充分确立。
大多数（96%）CD 的初次活检均异常，表现为活动性慢性回结肠炎，其中 80%（80%）非常高比例的病例显示出异常黏膜结构、上皮异常和活动性慢性炎症的经典组合。最敏感的特征是固有层慢性炎症（敏感性 92.7%）。其他特征的敏感性如下：活动性炎症 87.8%、基底浆细胞增多 82.1%、结构改变 80.5%和上皮异常 70.7%。回肠活检异常率为 94%，结肠活检异常率为 76%。没有任何特征是特异性的，因为所有结核病和憩室病病例均显示出经典组合。41 例 CD 中有 10 例、5 例结核病和 0 例憩室病活检中均可见肉芽肿。CD 的肉芽肿小而紧实、边界清晰，而结核病的肉芽肿则较大且融合。潘氏细胞和假幽门化生仅见于 CD（2/25）。
成人 CD 的初次内镜活检显著异常，大多数表现为活动性慢性回结肠炎。这些特征对于在适当的临床环境下初步诊断 CD 非常重要。除溃疡性结肠炎外，结核病和憩室病相关结肠炎是两种需要考虑的重要模拟疾病。
