title: The Temporal Evolution of Histological Abnormalities in Microscopic Colitis.
abstract: OBJECTIVE
  Microscopic colitis (MC) is a common cause of chronic watery diarrhoea but long-term follow-up data are sparse.
  
  
  METHODS
  We performed a retrospective review of health records and all pathology reports in a regional cohort of patients with MC to describe the change in pre- and post-diagnostic colon biopsies.
  
  
  RESULTS
  MC was diagnosed in 468 patients with collagenous colitis (CC), 361 with lymphocytic colitis (LC) and 226 with incomplete MC (MCi). The 2014 incidence of CC, LC and MCi was 14.5, 14.9 and 5 per 10(5). Biopsies from both right and left colon were obtained in 237 (51%) patients with CC, 200 (55%) with LC and 107 (47%) with MCi. The diagnostic sensitivities of both left- and right-sided biopsies for MC were high and did not differ. Pre-diagnostic biopsies were obtained in 150 patients and lamina propria inflammation was described in 59, 47 and 43% of patients with a diagnosis of CC, LC and MCi respectively within 1 year, while histology was normal in 16, 13 and 21%. Post-diagnostic biopsies were obtained in 283 patients. MC persisted for up to one year in 77% with CC, 64% with LC and 45% with MCi, of whom 6, 9 and 18% respectively changed to a different MC subgroup.
  
  
  CONCLUSIONS
  Colonic biopsies obtained prior to the MC diagnosis often revealed increased lamina propria inflammation. The pathological changes of CC and LC are more persistent than those of MCi. Biopsies from the descending or sigmoid colon are sufficient to elucidate whether a patient with chronic watery diarrhoea has MC.
authors.affiliation: Department of Medicine, Køge University Hospital, Køge, Denmark.
authors.forename: Julie
authors.initials: J
authors.lastname: Rasmussen
authors.affiliation: Department of Pathology, Roskilde University Hospital, Roskilde, Denmark Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Peter Johan Heiberg
authors.initials: PJ
authors.lastname: Engel
authors.affiliation: Department of Medicine, Køge University Hospital, Køge, Denmark.
authors.forename: Signe
authors.initials: S
authors.lastname: Wildt
authors.affiliation: Department of Pathology, Roskilde University Hospital, Roskilde, Denmark.
authors.forename: Anne-Marie Kanstrup
authors.initials: AM
authors.lastname: Fiehn
authors.affiliation: Department of Medicine, Køge University Hospital, Køge, Denmark Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark lkmu@regionsjaelland.dk.
authors.forename: Lars Kristian
authors.initials: LK
authors.lastname: Munck
mesh_terms: D000368:Aged; D001706:Biopsy; D046728:Colitis, Microscopic / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology*; D003106:Colon / Q000473:pathology*; D003718:Denmark / Q000453:epidemiology; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007413:Intestinal Mucosa / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013997:Time Factors
keywords: Microscopic colitis; endoscopy; pathology