DOP78 The differential diagnosis and clinicopathological spectrum of Inflammatory Bowel Disease: An interesting and informative ECCO topical review

Feakins , R.M.(1); Torres, J.(2); Borralho-Nunes, P.(3,4); Burisch, J.(5); Cúrdia Gonçalves, T.(6,7,8); De Ridder, L.(9); Driessen, A.(10); Lobatón, T.(11); Menchén, L.(12,13,14); Mookhoek, A.(15); Noor, N.(16); Svrcek, M.(17); Villanacci, V.(18); Zidar, N.(19); Tripathi, M.(20)

(1)Department of Cellular Pathology, Royal Free London NHS Trust, London, United Kingdom;(2)Department of Gastroenterology, Hospital Beatriz Ângelo, Loures, Portugal;(3)Department of Pathology, Hospital Cuf Descobertas, Lisbon, Portugal;(4)Faculdade de Medicina da Universidade de Lisboa, Lisbon, Portugal;(5)Gastrounit, medical division, Hvidovre Hospital, University of Copenhagen, Denmark;(6)Department of Gastroenterology, Hospital da Senhora da Oliveira, Guimarães, Portugal;(7)School of Medicine, University of Minho, Braga/Guimarães, Portugal;(8) ICVS/3B’s–PT Government Associate Laboratory, Braga/Guimarães, Portugal;(9)Department of Paediatric Gastroenterology, Erasmus MC Sophia Children’s Hospital, University Medical Center Rotterdam, The Netherlands;(10)Department of Pathology, University Hospital Antwerp, University Antwerp, Edegem, Belgium;(11)Department of Gastroenterology, Ghent University Hospital, Ghent, Belgium;(12)Department of Digestive System Medicine, Hospital General Universitario-Insitituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain;(13)Department of Medicine, Universidad Complutense, Madrid, Spain;(14)Centro de Investigación Biomédica En Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Madrid, Spain;(15)Department of Pathology, Amsterdam UMC, Amsterdam, The Netherlands;(16)Department of Gastroenterology, Addenbrooke's Hospital, Cambridge University Hospitals NHS Trust, Cambridge, United Kingdom;(17)Department of Pathology, Sorbonne Université, AP-HP, Saint-Antoine hospital, Paris, France;(18)Departments of Histopathology, Spedali Civili and University of Brescia, Brescia, Italy;(19)Institute of Pathology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia;(20)Department of Histopathology, Cambridge Biomedical Campus, Addenbrooke’s Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom; TR Clinicopathological spectrum and differential diagnosis of IBD

Background

A wide variety of intestinal and non-intestinal diseases can resemble chronic idiopathic inflammatory bowel disease (IBD) clinically and/or pathologically. The aim of the current Topical Review was to explore the differential diagnosis of IBD and to discuss clinical, histomorphological features and ancillary techniques that help distinguish between IBD and its mimics.

Methods

An open ECCO call led to the selection of 12 participants who formed three working groups (WG) to study the mimics of IBD. WG 1 comprised gastroenterologists, who explored mainly the clinical features. WG 2 consisted of histopathologists, who focused on macroscopic and microscopic pathological aspects. WG 3 was a mixed group of pathologists and clinicians who studied the value of additional investigative techniques such as imaging, serology and molecular markers. A systematic literature search allowed exploration of these topics and the identification of the most helpful and relevant distinguishing features. The process led to the development of Current Practice Position (CPP) statements and supporting text. Consensus meetings with voting by all participants facilitated modification and finalisation of CPP statements.

Results

The project highlighted several points. Firstly, there is a wide and sometimes overwhelming variety of potential mimics of new and established IBD, both in adults and in children. 
Secondly, some mimics are more important clinically and others pathologically, meaning that the emphasis on the mimics of IBD is different for clinicians and pathologists. Thirdly, close attention to all clinical features, pathological findings and other evidence optimises accuracy. Finally, newer techniques sometimes have a role, e.g., in distinguishing monogenic IBD-like disorders from IBD in young children, and the value of many novel techniques is as yet uncertain. A practical message is that constant awareness by clinicians and pathologists of the possibility of mimics is particularly important.
 

Conclusion

Discussions between pathologists and clinicians were particularly useful during this process and were a reminder of the importance of clinicopathological correlation. There is a wide variety of mimics of IBD, including infections, diverticular disease, drug effect, radiation damage, immune disorders, vascular disorders and diversion proctocolitis. An important, relatively new, and sometimes very close mimic of IBD is immune checkpoint inhibitor colitis. In turn, reliable distinction between IBD and other entities requires a multidisciplinary approach with a full clinical history (including duration of disease), and with appropriate investigations that may include endoscopy, pathology, imaging, microbiological tests, serology, and newer molecular tests.