Microscopic Colitis: A Challenging Disorder

Abstract

Background: The clinical importance of microscopic colitis (MC) is increasing. This is explained by both the increasing incidence and the challenges posed by the disease. However, recent MC data also reveal a number of doubts and uncertainties. Summary: This review focuses on current knowledge of MC and highlights the various controversies and criticisms regarding the clinical data about definitions, subtypes, pathogenesis, diagnosis, and treatment of this condition. Key Messages: The diagnosis of MC is based on histology, which distinguishes 2 subtypes. However, transitional forms often cause misclassification, which calls into question the reality (specificity, meaning) of the distinction between the 2 forms. The location of the colon biopsy is not defined by international consensus. There is no credible, clear explanation for the incidence increase. The pathogenesis is unknown, probably multifactorial, but the importance of the immunological background is increasing. The natural history of the disease and the underlying cause of relapses are unclear. It is suggested that MC would be the prelude of IBD. Further data collection is needed to clarify these issues.

Description of Colonoscopy and Histopathology of Chronic Diarrhea Causes in Non-Neoplasm: Literature Review

“…In lymphocytic colitis, the following were found: increased surface intraepithelial lymphocytes >20 per 100 epithelial cell, increased inflammation in lamina propria, and flat surface epithelial damage, mucin depletion, and vacuolization, and absence of collagen thickening in the subepithelial or slightly thickened subepithelial collagen. 33,37,38,39,40 Meanwhile, in collagenous colitis, the following were found: thickened subepithelial collagen band >10 µm, increased inflammation in lamina propria, subepithelial surface, and epithelial surface damage nearly the same as lymphocytic colitis. 33,34,38,39…”

“…In the abnormal mucosa, there could be found inflammation signs such as erythema, irregular vascular pattern, presence of oedema, formation of linear ulceration, a bit of mucosal laceration and mucosal nodularity. 34,32,39,40 Furthermore, histopathology identification was conducted on microscopic colitis to differentiate each types of microscopic colitis. In lymphocytic colitis, the following were found: increased surface intraepithelial lymphocytes >20 per 100 epithelial cell, increased inflammation in lamina propria, and flat surface epithelial damage, mucin depletion, and vacuolization, and absence of collagen thickening in the subepithelial or slightly thickened subepithelial collagen.…”

“…Furthermore, histopathology in incomplete collagenous colitis were thickened subepithelial collagenous band > 5 to ≤ 10 µm. 34,38,39,40…”

Colitis microscópica, serie de casos y revisión de la literatura

“…En cuanto a la etiopatogenia, es una enfermedad multifactorial, relacionada en los últimos años con factores inmunológicos, por lo cual algunos autores consideran a la CM como una etapa inicial de la EII. El diagnóstico se confirma mediante el estudio histológico, pero no hay consenso con respecto a la cantidad de biopsias a tomar; algunos estudios recomiendan la toma de hasta 8 biopsias en cada segmento colónico para lograr el diagnóstico (5) .…”

“…Se consideran 3 tipos de CM: la CL, en la cual se observa una inflamación crónica de la lámina propia, y el criterio diagnóstico es la presencia de más de 20 linfocitos por cada 100 células epiteliales; la CC, en la que el criterio diagnóstico es el engrosamiento de la capa de colágeno > 10 μm; y la colitis microscópica inespecífica (CMI), con síntomas típicos de CM, pero sin los cambios histológicos descritos, la relación de linfocitos y de células plasmáticas es < 10/100, o la capa de colágeno tiene un espesor < 10 μm, razón por la cual diversos investigadores consideran que las dos formas inicialmente mencionadas no corresponden a dos enfermedades diferentes, sino a dos estadios diferentes de una misma enfermedad (5) .…”