Case series
Microscopic colitis: a misnomer for a clearly defined entity?
Authors
Diana E. Yung1, Anastasios Koulaouzidis2, 3, Paul Fineron4, John N. Plevris2, 3
Institutions
1
Victoria Hospital, Kirkcaldy, UK Endoscopy Unit, The Royal Infirmary of Edinburgh, UK 3 Medical School, The University of Edinburgh, UK 4 Pathology Department, The Western General Hospital, Edinburgh, UK 2
submitted 19. December 2014 accepted after revision 9. February 2015
Bibliography DOI http://dx.doi.org/ 10.1055/s-0034-1391986 Published online: 11.5.2015 Endoscopy 2015; 47: 754–757 © Georg Thieme Verlag KG Stuttgart · New York ISSN 0013-726X Corresponding author A. Koulaouzidis, MD Endoscopy Unit The Royal Infirmary of Edinburgh 51 Little France Crescent Edinburgh EH16 4SA UK [email protected]
In recent years, several endoscopic features of microscopic colitis have been noted. The pickup of these on colonoscopy depends on local expertise, endoscopic technology, and case volume. As the incidence of microscopic colitis has increased, we wanted to draw attention to endoscopists’ ability to recognize such findings. We present eight cases
of biopsy-proven microscopic colitis which demonstrate the spectrum of endoscopic findings. Endoscopists should actively search for such findings and target their biopsies, as new high-definition colonoscopes with sharper images, zoom capabilities, and high resolution allow a new vision into this syndrome.
Introduction
trum of endoscopic findings. The colonoscopist should actively search for such findings rather than rely on random endoscopic biopsies if there is a suspicion of microscopic colitis. This series therefore aims to promote awareness of the macroscopic findings of microscopic colitis amongst endoscopists and to encourage more proactive/ positive diagnosis of microscopic colitis.
!
Collagenous colitis (CGC) is one of the two main forms of microscopic colitis, a term used to denote the absence of consistent macroscopic findings during colonoscopy in patients with CGC or lymphocytic colitis (LCC) [1, 2]. However, over recent years, several endoscopic features have been noted. A recent systematic review associated the following findings with CGC: alteration of the vascular mucosal pattern (hyperemia and/or dwindling of mucosal vasculature), mucosal nodularity, a sequence of change from mucosal defects to mucosal scars, and pseudomembranes [3]. Pickup of CGC on colonoscopy depends on local expertise, available endoscopic technology, endoscopy volumes at various centers, and subspecialty interest of individual endoscopists [4]. Although white-light endoscopy remains mainstream, image-enhancement techniques such as chromoendoscopy, narrow-band imaging (NBI), and Fuji Intelligent Chromoendoscopy (FICE) have helped in recognizing mucosal patterns suggestive of microscopic colitis in a way that was not previously possible [5 – 7]. Current guidelines require multiple biopsy samples from the right and left side of the colon for definitive diagnosis of CGC [8]. As the incidence of microscopic colitis has increased, we thought that attention should be refocused on endoscopists’ ability to recognize such endoscopic findings, either with standard white-light or high-definition colonoscopy. We present eight cases of biopsy-proven microscopic colitis, which demonstrate the wide spec-
Yung Diana E et al. Microscopic colitis … Endoscopy 2015; 47: 754–757
Case series !
Eight patients (mean age 73; 7 women, 1 man) " Table 1) were referred for investigation of wa(● tery diarrhea. Colonoscopies were performed using either Olympus or Fujinon/Fujifilm 600 series colonoscopes and showed striking endoscopic features that have previously been suggested as being consistent with microscopic coli" Fig. 1, " Fig. e2, and " Fig. e3). Two patis [3] (● ● ● tients had a medical history that included breast cancer, while another two had chronic renal disease. Three patients had hypothyroidism, reflecting the known association between CGC and autoimmune disease, especially thyroid conditions [2]. Four patients reported a possible precipitating factor for their symptoms: onset of symptoms in two patients appeared to be associated with medications – lansoprazole and statins – and in another two patients followed other illnesses – infectious gastroenteritis and nocturnal diarrhea after a myocardial infarction.
Downloaded by: Karolinska Institutet. Copyrighted material.
754
years
89 F
42 M
74 F
76 F
89 F
69 F
81 F
2
3
4
5
6
7
8
2 weeks of persistent diarrhea
CGC 2008, spontaneous remission 2009; recurrent diarrhea with tenesmus, mucus, and blood after starting statins
2 weeks of explosive watery diarrhea, resolved by time of endoscopy
Nocturnal diarrhea following myocardial infarction
Loose stools, weight loss
Diarrhea and weight loss following infectious gastroenteritis. Initially high FCP
Diarrhea, vomiting, dehydration, watery stools. Use of lansoprazole.
3 years of intermittent diarrhea and weight loss
Presenting symptoms
“Cat scratch” appearance of ascending colon
–
Asacol, budesonide
Hypothyroidism
–
Hypothyroidism, chronic kidney disease stage 3, myocardial infarction
Loperamide
Pruning of mucosal vasculature in rectum and sigmoid, mucosal hyperemia in transverse colon, lacerations in ascending colon
–
NSTEMI, percutaneous coronary intervention, stroke, breast carcinoma, duodenal ulcer
Mucosal haziness, patchy erythema right colon, distal lacerations
Edema, peau d’orange mucosa in ascending colon
Dwindling of vasculature in descending colon, patchy erythema in terminal ileum with mucosal fragility on FICE
–
Cryoglobulinemia, leukocytoclastic vasculitis with skin & renal involvement, anemia, hypothyroidism
Pseudo-membranes
Metronidazole, budesonide
–
Mucosal fractures in left colon (proximal descending to sigmoid)
Mucosal sores in left colon (proximal sigmoid to distal descending)
Endoscopic findings
Budesonide
–
Treatment
Pseudogout, gallbladder empyema and cholecystectomy, asthma, colovaginal fistula requiring anterior resection
Scleroderma, rheumatoid arthritis, breast carcinoma
Relevant medical history
Olympus 260 series
Fujinon 600 series
Unknown
Unknown
Fujinon 600 series
Olympus 260 series
Fujinon 530 series
Olympus 260 series
used
Colono-scope
Yung Diana E et al. Microscopic colitis … Endoscopy 2015; 47: 754–757
Downloaded by: Karolinska Institutet. Copyrighted material.
M, male; F, Female; C. difficile, Clostridium difficile; FCP, faecal calprotectin; FICE, Fuji Intelligent Chromoendoscopy, NSTEMI, non-ST elevation myocardial infarction.
64 F
1
Sex
Age,
number
Cecum × 4 Mid transverse × 4 and distal sigmoid colon ×4
Ascending × 6 and transverse colon × 5 Rectum × 2
Proximal ascending ×4 mid transverse × 4 and proximal descending colon × 4
Proximal ascending ×6 and mid transverse colon × 4 Rectum × 2
Terminal ileum × 4 Cecum × 4 Distal ascending × 8 and proximal descending colon × 4 Rectum × 2
Descending and sigmoid colon, rectum
Terminal ileum × 3 Proximal ascending colon to rectum × 4 Proximal descending colon to sigmoid × 4
Proximal transverse × 2 and distal descending colon × 2
Biopsy site
Baseline data, endoscopic findings and outcomes of eight patients who were found to have biopsy-proven collagenous colitis (CGC) or lymphocytic colitis (LCC).
Patient
Table 1
Micro-scopic colitis, likely CGC
CGC
CGC
LCC
CGC
CGC
CGC
CGC
CGC/ LCC
–
–
–
–
–
Stool negative for C. difficile toxin Symptoms eventually resolved spontaneously
Perforated duodenal ulcer on budesonide; symptoms recurred on stopping and controlled by higher doses; spontaneous resolution (with normal biopsy) after 1 year
Resolved spontaneously
Follow-up/sequelae
Case series
755
Case series
Fig. 1 The endoscopic features that have been reported to be consistent with microscopic colitis include: a dwindling vasculature and blotchy erythema, seen using Fuji Intelligent Chromoendoscopy (FICE); b blotchy and punctate mucosal erythema and friability with deranged vasculature; c deranged mucosal vasculature, seen using FICE; d nodular mucosa, seen after targeted spraying with indigo carmine 1 %; e mosaic/celiac-like mucosa, seen using FICE; f “cat-scratch” appearance of the mucosa.
Criteria for histologic diagnoses of CGC or LCC CGC was diagnosed on the basis of increased lamina propria cellularity, inflammatory cells in the epithelial surface, abnormal subepithelial collagenous band with separation of the epithelium, and irregular and degenerate hypereosinophilic strands of collagen dipping into the lamina propria. LCC was diagnosed on the basis of increased lamina propria cellularity, increased intraepithelial lymphocytes ( ≥ 25 /100 surface epithelial cells), evidence of epithelial injury (loss of mucin, nuclear irregularity, flattening), and normal crypt architecture.
Discussion !
The use of the term microscopic colitis is to a certain degree “restrictive,” as it may prohibit a closer look into an ever-increasing body of evidence of macroscopic findings in such cases. The aim of this case series was to document the macroscopic changes, so lowering the threshold for detection and diagnosis of microscopic colitis. Furthermore, as such lesions can be patchy, the identification of subtle colonic mucosal abnormalities may help to guide biopsies and reduce the false-negative rate. CGC has emerged as the commoner of the two forms of microscopic colitis, a colitic syndrome with distinctive histopathologic findings and macroscopically normal or “near normal” colonoscopy [1, 3, 8]. Epidemiologic studies show that microscopic colitis is almost as common as the classic inflammatory bowel diseases,
Yung Diana E et al. Microscopic colitis … Endoscopy 2015; 47: 754–757
Crohn’s disease and ulcerative colitis; nevertheless CGC is still under-recognized in clinical/endoscopic practice [1]. A recent study has shown that endoscopists with a gastroenterology background were more likely to pick up microscopic colitis, compared with those who came from a different specialty background, such as internal medicine or surgery [4]. This may reflect some lack of awareness or expertise in microscopic colitis. It is possible that the use of older generation colonoscopes with lower image definition and clarity would have allowed features such as subtle alteration of the mucosal surface or submucosal vasculature changes to go unnoticed, unless chromoendoscopy techniques were applied [3, 5 – 7, 9]. The new high-definition colonoscopes with sharper images, zoom capabilities, and high resolution should allow a new vision of the microscopic colitis syndrome. This cases series represents the complete spectrum of endoscopic findings in microscopic colitis that have been described to date [3, 5]. These range from mucosal congestion to ulceration, to pseudomembranes and mucopurulent exudate (as in patient #3). Previous studies have reported nonspecific edema and erythema in up to one-third of patients with microscopic colitis. Another study has suggested that a mosaic pattern seen in the colorectal mucosa of patients with chronic diarrhea could be indicative of CGC [10]. Although indigo-carmine endoscopy has been used to make a CGC diagnosis [5] and the usefulness of narrowband imaging in this setting has been reported in one other case, to our knowledge this is the first publication to provide FICE images of CGC.
Downloaded by: Karolinska Institutet. Copyrighted material.
756
Although microscopic colitis is currently thought to follow a much more benign clinical course than ulcerative colitis or Crohn’s disease [1, 2], it may not be as benign as previously thought, as there are case reports describing serious complications such as perforation [11]. Patient #2 in our series had diarrhea that was severe enough to cause dehydration. There is also some evidence of a link between CGC and malignancy, which has been reported in up to 10 % of cases either predating or following the diagnosis of microscopic colitis [2, 12], and this deserves further attention. Biopsy protocols vary but it is recommended to obtain at least two biopsies from the ascending, transverse, descending, and sigmoid colon, and the rectum, in order to achieve a sensitivity of > 95 % [2]. In future, such work may be expanded to produce a European Microscopic Colitis Group (EMCG)-supported classification or atlas of macroscopic findings in microscopic colitis. This could be achieved through larger multicenter studies. Competing interests: None
References 1 Münch A, Aust D, Bohr J et al. European Microscopic Colitis Group (EMCG). Microscopic colitis: Current status, present and future challenges: statements of the European Microscopic Colitis Group. J Crohns Colitis 2012; 6: 932 – 945
2 Storr MA. Microscopic colitis: epidemiology, pathophysiology, diagnosis and current management – an update 2013. ISRN Gastroenterology 2013: Article ID: 352718 3 Koulaouzidis XXXX, Saeed AA. Distinct colonoscopy findings of microscopic colitis: not so microscopic after all? World J Gastroenterol 2011; 17: 4157 – 4165 4 Andrews CN, Beck PL, Wilsack LH et al. Evaluation of endoscopist and pathologist factors affecting the incidence of microscopic colitis. Can J Gastroenterol 2012; 26: 515 – 520 5 Suzuki G, Mellander MR, Suzuki A et al. Usefulness of colonoscopic examination with indigo carmine in diagnosing microscopic colitis. Endoscopy 2011; 43: 1100 – 1104 6 Kiesslich R, Hoffman A, Goetz M et al. In vivo diagnosis of collagenous colitis by confocal endomicroscopy. Gut 2006; 55: 591 – 592 7 Morita T, Yamamoto S, Takeuchi E. Narrow band imaging for diagnosis of collagenous colitis. Dig Endosc 2014; 26: 752 – 753 8 Bateman AC, Patel P. Lower gastrointestinal endoscopy: guidance on indications for biopsy. Frontline Gastroenterol 2013: DOI: DOI 10.1136/flgastro-2013-100412 9 Park HS, Han DS, Ro Y et al. Does lymphocytic colitis always present with normal endoscopic findings? Gut Liver DOI: DOI 2014.10.5009/ gnl13373 10 Cimmino DG, Mella JM, Pereyra L et al. A colorectal mosaic pattern might be an endoscopic feature of collagenous colitis. J Crohns Colitis 2010; 4: 139 – 143 11 Wickbom A, Lindqvist M, Bohr J et al. Colonic mucosal tears in collagenous colitis. Scand J Gastroenterol 2006; 41: 726 – 729 12 Madalinski M, Koulaouzidis A. Collagenous colitis with mucosal tears in two proton pump inhibitors and non-steroidal naive patients who developed metachronous cancer. J Dig Dis 2013; 14: 51 – 53
Fig. e2 and e3 online content viewable at: http://dx.doi.org/10.1055/s-0034-1391986
Yung Diana E et al. Microscopic colitis … Endoscopy 2015; 47: 754–757
757
Downloaded by: Karolinska Institutet. Copyrighted material.
Case series
Microscopic colitis: a misnomer for a clearly defined entity?
Authors
Diana E. Yung1, Anastasios Koulaouzidis2, 3, Paul Fineron4, John N. Plevris2, 3
Institutions
1
Victoria Hospital, Kirkcaldy, UK Endoscopy Unit, The Royal Infirmary of Edinburgh, UK 3 Medical School, The University of Edinburgh, UK 4 Pathology Department, The Western General Hospital, Edinburgh, UK 2
submitted 19. December 2014 accepted after revision 9. February 2015
Bibliography DOI http://dx.doi.org/ 10.1055/s-0034-1391986 Published online: 11.5.2015 Endoscopy 2015; 47: 754–757 © Georg Thieme Verlag KG Stuttgart · New York ISSN 0013-726X Corresponding author A. Koulaouzidis, MD Endoscopy Unit The Royal Infirmary of Edinburgh 51 Little France Crescent Edinburgh EH16 4SA UK [email protected]
In recent years, several endoscopic features of microscopic colitis have been noted. The pickup of these on colonoscopy depends on local expertise, endoscopic technology, and case volume. As the incidence of microscopic colitis has increased, we wanted to draw attention to endoscopists’ ability to recognize such findings. We present eight cases
of biopsy-proven microscopic colitis which demonstrate the spectrum of endoscopic findings. Endoscopists should actively search for such findings and target their biopsies, as new high-definition colonoscopes with sharper images, zoom capabilities, and high resolution allow a new vision into this syndrome.
Introduction
trum of endoscopic findings. The colonoscopist should actively search for such findings rather than rely on random endoscopic biopsies if there is a suspicion of microscopic colitis. This series therefore aims to promote awareness of the macroscopic findings of microscopic colitis amongst endoscopists and to encourage more proactive/ positive diagnosis of microscopic colitis.
!
Collagenous colitis (CGC) is one of the two main forms of microscopic colitis, a term used to denote the absence of consistent macroscopic findings during colonoscopy in patients with CGC or lymphocytic colitis (LCC) [1, 2]. However, over recent years, several endoscopic features have been noted. A recent systematic review associated the following findings with CGC: alteration of the vascular mucosal pattern (hyperemia and/or dwindling of mucosal vasculature), mucosal nodularity, a sequence of change from mucosal defects to mucosal scars, and pseudomembranes [3]. Pickup of CGC on colonoscopy depends on local expertise, available endoscopic technology, endoscopy volumes at various centers, and subspecialty interest of individual endoscopists [4]. Although white-light endoscopy remains mainstream, image-enhancement techniques such as chromoendoscopy, narrow-band imaging (NBI), and Fuji Intelligent Chromoendoscopy (FICE) have helped in recognizing mucosal patterns suggestive of microscopic colitis in a way that was not previously possible [5 – 7]. Current guidelines require multiple biopsy samples from the right and left side of the colon for definitive diagnosis of CGC [8]. As the incidence of microscopic colitis has increased, we thought that attention should be refocused on endoscopists’ ability to recognize such endoscopic findings, either with standard white-light or high-definition colonoscopy. We present eight cases of biopsy-proven microscopic colitis, which demonstrate the wide spec-
Yung Diana E et al. Microscopic colitis … Endoscopy 2015; 47: 754–757
Case series !
Eight patients (mean age 73; 7 women, 1 man) " Table 1) were referred for investigation of wa(● tery diarrhea. Colonoscopies were performed using either Olympus or Fujinon/Fujifilm 600 series colonoscopes and showed striking endoscopic features that have previously been suggested as being consistent with microscopic coli" Fig. 1, " Fig. e2, and " Fig. e3). Two patis [3] (● ● ● tients had a medical history that included breast cancer, while another two had chronic renal disease. Three patients had hypothyroidism, reflecting the known association between CGC and autoimmune disease, especially thyroid conditions [2]. Four patients reported a possible precipitating factor for their symptoms: onset of symptoms in two patients appeared to be associated with medications – lansoprazole and statins – and in another two patients followed other illnesses – infectious gastroenteritis and nocturnal diarrhea after a myocardial infarction.
Downloaded by: Karolinska Institutet. Copyrighted material.
754
years
89 F
42 M
74 F
76 F
89 F
69 F
81 F
2
3
4
5
6
7
8
2 weeks of persistent diarrhea
CGC 2008, spontaneous remission 2009; recurrent diarrhea with tenesmus, mucus, and blood after starting statins
2 weeks of explosive watery diarrhea, resolved by time of endoscopy
Nocturnal diarrhea following myocardial infarction
Loose stools, weight loss
Diarrhea and weight loss following infectious gastroenteritis. Initially high FCP
Diarrhea, vomiting, dehydration, watery stools. Use of lansoprazole.
3 years of intermittent diarrhea and weight loss
Presenting symptoms
“Cat scratch” appearance of ascending colon
–
Asacol, budesonide
Hypothyroidism
–
Hypothyroidism, chronic kidney disease stage 3, myocardial infarction
Loperamide
Pruning of mucosal vasculature in rectum and sigmoid, mucosal hyperemia in transverse colon, lacerations in ascending colon
–
NSTEMI, percutaneous coronary intervention, stroke, breast carcinoma, duodenal ulcer
Mucosal haziness, patchy erythema right colon, distal lacerations
Edema, peau d’orange mucosa in ascending colon
Dwindling of vasculature in descending colon, patchy erythema in terminal ileum with mucosal fragility on FICE
–
Cryoglobulinemia, leukocytoclastic vasculitis with skin & renal involvement, anemia, hypothyroidism
Pseudo-membranes
Metronidazole, budesonide
–
Mucosal fractures in left colon (proximal descending to sigmoid)
Mucosal sores in left colon (proximal sigmoid to distal descending)
Endoscopic findings
Budesonide
–
Treatment
Pseudogout, gallbladder empyema and cholecystectomy, asthma, colovaginal fistula requiring anterior resection
Scleroderma, rheumatoid arthritis, breast carcinoma
Relevant medical history
Olympus 260 series
Fujinon 600 series
Unknown
Unknown
Fujinon 600 series
Olympus 260 series
Fujinon 530 series
Olympus 260 series
used
Colono-scope
Yung Diana E et al. Microscopic colitis … Endoscopy 2015; 47: 754–757
Downloaded by: Karolinska Institutet. Copyrighted material.
M, male; F, Female; C. difficile, Clostridium difficile; FCP, faecal calprotectin; FICE, Fuji Intelligent Chromoendoscopy, NSTEMI, non-ST elevation myocardial infarction.
64 F
1
Sex
Age,
number
Cecum × 4 Mid transverse × 4 and distal sigmoid colon ×4
Ascending × 6 and transverse colon × 5 Rectum × 2
Proximal ascending ×4 mid transverse × 4 and proximal descending colon × 4
Proximal ascending ×6 and mid transverse colon × 4 Rectum × 2
Terminal ileum × 4 Cecum × 4 Distal ascending × 8 and proximal descending colon × 4 Rectum × 2
Descending and sigmoid colon, rectum
Terminal ileum × 3 Proximal ascending colon to rectum × 4 Proximal descending colon to sigmoid × 4
Proximal transverse × 2 and distal descending colon × 2
Biopsy site
Baseline data, endoscopic findings and outcomes of eight patients who were found to have biopsy-proven collagenous colitis (CGC) or lymphocytic colitis (LCC).
Patient
Table 1
Micro-scopic colitis, likely CGC
CGC
CGC
LCC
CGC
CGC
CGC
CGC
CGC/ LCC
–
–
–
–
–
Stool negative for C. difficile toxin Symptoms eventually resolved spontaneously
Perforated duodenal ulcer on budesonide; symptoms recurred on stopping and controlled by higher doses; spontaneous resolution (with normal biopsy) after 1 year
Resolved spontaneously
Follow-up/sequelae
Case series
755
Case series
Fig. 1 The endoscopic features that have been reported to be consistent with microscopic colitis include: a dwindling vasculature and blotchy erythema, seen using Fuji Intelligent Chromoendoscopy (FICE); b blotchy and punctate mucosal erythema and friability with deranged vasculature; c deranged mucosal vasculature, seen using FICE; d nodular mucosa, seen after targeted spraying with indigo carmine 1 %; e mosaic/celiac-like mucosa, seen using FICE; f “cat-scratch” appearance of the mucosa.
Criteria for histologic diagnoses of CGC or LCC CGC was diagnosed on the basis of increased lamina propria cellularity, inflammatory cells in the epithelial surface, abnormal subepithelial collagenous band with separation of the epithelium, and irregular and degenerate hypereosinophilic strands of collagen dipping into the lamina propria. LCC was diagnosed on the basis of increased lamina propria cellularity, increased intraepithelial lymphocytes ( ≥ 25 /100 surface epithelial cells), evidence of epithelial injury (loss of mucin, nuclear irregularity, flattening), and normal crypt architecture.
Discussion !
The use of the term microscopic colitis is to a certain degree “restrictive,” as it may prohibit a closer look into an ever-increasing body of evidence of macroscopic findings in such cases. The aim of this case series was to document the macroscopic changes, so lowering the threshold for detection and diagnosis of microscopic colitis. Furthermore, as such lesions can be patchy, the identification of subtle colonic mucosal abnormalities may help to guide biopsies and reduce the false-negative rate. CGC has emerged as the commoner of the two forms of microscopic colitis, a colitic syndrome with distinctive histopathologic findings and macroscopically normal or “near normal” colonoscopy [1, 3, 8]. Epidemiologic studies show that microscopic colitis is almost as common as the classic inflammatory bowel diseases,
Yung Diana E et al. Microscopic colitis … Endoscopy 2015; 47: 754–757
Crohn’s disease and ulcerative colitis; nevertheless CGC is still under-recognized in clinical/endoscopic practice [1]. A recent study has shown that endoscopists with a gastroenterology background were more likely to pick up microscopic colitis, compared with those who came from a different specialty background, such as internal medicine or surgery [4]. This may reflect some lack of awareness or expertise in microscopic colitis. It is possible that the use of older generation colonoscopes with lower image definition and clarity would have allowed features such as subtle alteration of the mucosal surface or submucosal vasculature changes to go unnoticed, unless chromoendoscopy techniques were applied [3, 5 – 7, 9]. The new high-definition colonoscopes with sharper images, zoom capabilities, and high resolution should allow a new vision of the microscopic colitis syndrome. This cases series represents the complete spectrum of endoscopic findings in microscopic colitis that have been described to date [3, 5]. These range from mucosal congestion to ulceration, to pseudomembranes and mucopurulent exudate (as in patient #3). Previous studies have reported nonspecific edema and erythema in up to one-third of patients with microscopic colitis. Another study has suggested that a mosaic pattern seen in the colorectal mucosa of patients with chronic diarrhea could be indicative of CGC [10]. Although indigo-carmine endoscopy has been used to make a CGC diagnosis [5] and the usefulness of narrowband imaging in this setting has been reported in one other case, to our knowledge this is the first publication to provide FICE images of CGC.
Downloaded by: Karolinska Institutet. Copyrighted material.
756
Although microscopic colitis is currently thought to follow a much more benign clinical course than ulcerative colitis or Crohn’s disease [1, 2], it may not be as benign as previously thought, as there are case reports describing serious complications such as perforation [11]. Patient #2 in our series had diarrhea that was severe enough to cause dehydration. There is also some evidence of a link between CGC and malignancy, which has been reported in up to 10 % of cases either predating or following the diagnosis of microscopic colitis [2, 12], and this deserves further attention. Biopsy protocols vary but it is recommended to obtain at least two biopsies from the ascending, transverse, descending, and sigmoid colon, and the rectum, in order to achieve a sensitivity of > 95 % [2]. In future, such work may be expanded to produce a European Microscopic Colitis Group (EMCG)-supported classification or atlas of macroscopic findings in microscopic colitis. This could be achieved through larger multicenter studies. Competing interests: None
References 1 Münch A, Aust D, Bohr J et al. European Microscopic Colitis Group (EMCG). Microscopic colitis: Current status, present and future challenges: statements of the European Microscopic Colitis Group. J Crohns Colitis 2012; 6: 932 – 945
2 Storr MA. Microscopic colitis: epidemiology, pathophysiology, diagnosis and current management – an update 2013. ISRN Gastroenterology 2013: Article ID: 352718 3 Koulaouzidis XXXX, Saeed AA. Distinct colonoscopy findings of microscopic colitis: not so microscopic after all? World J Gastroenterol 2011; 17: 4157 – 4165 4 Andrews CN, Beck PL, Wilsack LH et al. Evaluation of endoscopist and pathologist factors affecting the incidence of microscopic colitis. Can J Gastroenterol 2012; 26: 515 – 520 5 Suzuki G, Mellander MR, Suzuki A et al. Usefulness of colonoscopic examination with indigo carmine in diagnosing microscopic colitis. Endoscopy 2011; 43: 1100 – 1104 6 Kiesslich R, Hoffman A, Goetz M et al. In vivo diagnosis of collagenous colitis by confocal endomicroscopy. Gut 2006; 55: 591 – 592 7 Morita T, Yamamoto S, Takeuchi E. Narrow band imaging for diagnosis of collagenous colitis. Dig Endosc 2014; 26: 752 – 753 8 Bateman AC, Patel P. Lower gastrointestinal endoscopy: guidance on indications for biopsy. Frontline Gastroenterol 2013: DOI: DOI 10.1136/flgastro-2013-100412 9 Park HS, Han DS, Ro Y et al. Does lymphocytic colitis always present with normal endoscopic findings? Gut Liver DOI: DOI 2014.10.5009/ gnl13373 10 Cimmino DG, Mella JM, Pereyra L et al. A colorectal mosaic pattern might be an endoscopic feature of collagenous colitis. J Crohns Colitis 2010; 4: 139 – 143 11 Wickbom A, Lindqvist M, Bohr J et al. Colonic mucosal tears in collagenous colitis. Scand J Gastroenterol 2006; 41: 726 – 729 12 Madalinski M, Koulaouzidis A. Collagenous colitis with mucosal tears in two proton pump inhibitors and non-steroidal naive patients who developed metachronous cancer. J Dig Dis 2013; 14: 51 – 53
Fig. e2 and e3 online content viewable at: http://dx.doi.org/10.1055/s-0034-1391986
Yung Diana E et al. Microscopic colitis … Endoscopy 2015; 47: 754–757
757
Downloaded by: Karolinska Institutet. Copyrighted material.
Case series
