Collagenous Enterocolitis: Efficacy of Different Techniques in Revealing the Subepithelial Collagen Band

Original article


Fathi O. Dakhil, Fiona M. Stevens

Department of Medicine, Al-Arab Medical University, Benghazi, Libya

JMJ 2008,Vol.8, No.3: 173-179


Background: Collagenous colitis (CC) is underdiagnosed and a major cause of chronic diarrhoea in the elderly. It is characterized by a thick subepithelial collagen band; (CB >10um). Aims: We undertook this study to compare the efficacy of the different staining methods in detecting CC, and to determine if the newly described technique: examination of H&E sections by fluorescence microscopy (FHE) is superior to routine methods for assessing the subepithelial CB depth. Methods: 245 endoscopic biopsies were studied from 199 symptomatic patients: 140 female, 59 male (small intestinal 151, gastric 27, colorectal 21). Fifty-four were cases of coeliac disease. Histological, histochemical, and immunohistochemical studies were performed and slides were examined by light microscopy (LM). In addition H&E sections were also visualized by fluorescence microscopy. Employing Image Analysis Software, collagen band thickness was measured on identical or consecutive 5 µm sections of coded biopsies, using different staining and illumination techniques. Results: CB depth measurements in 21 colorectal biopsies: H&E mean 5.2 um (range 1.7-17.2; SD 3.7), van Gieson 4.4 µm (1.2-11.0; 2.9), FHE 7.0 µm (2.0-21.1; 4.8). Of the 21 biopsies, 15 were < 7 µm, 6 were > 7µm. In 4, the thickness under LM was equivocal (7-10µm); however, using FHE, the CB measured > 10 µm consistent with CC. Conclusions: FHE dramatically enhances the visibility of the CB enabling a diagnosis of CC to be confirmed or refuted. This technique is cheap; it uses standard equipment and is applicable to new and archival H&E sections.

Keywords: Collagenous colitis, Microscopic colitis, Coeliac disease, Fluorescence microscope, Tenascin.