Tropical Gastroenterology 2011;32(2):87–93 Editorial Ulcerative Colitis: The scope of the scopes in nomenclature and diagnosis S. Datta Gupta Department of Pathology Life-long learning is the hall-mark of professional education. This is often the result of All India Institute of Medical Sciences experiences shared by our colleagues world-wide, of common clinical conditions that present New Delhi - 110029, India in an unusual manner. Correspondence: The two major constituents of inflammatory bowel disease: Crohn’s disease (CD) and Dr. S. Datta Gupta ulcerative colitis (UC) have several overlapping features and their distinction in difficult Email: [email protected] cases is a true accreditation of the skills of a gastroenterologist. Indistinguishable cases are aptly labeled as indeterminate colitis. In certain countries such as India, additionally, colonic tuberculosis (TB) is a close differential of colonic Crohn’s disease mainly because both are recognized to show patchy involvement and granulomatous inflammation. In this issue of the journal, Shah SN, Amarapurkar AD, Thiruvengadam NR, Nistala S and Rathi PM1 highlight unusual presentations of ulcerative colitis that may make the diagnosis otherwise difficult. Non-contagious diarrheal diseases have been apparent to physicians over centuries having been described by Aretaeus (A.D. 300) and Soranus (A.D. 117).2 Sir Samuel Wilks in 18593 has been credited with introducing the term “ulcerative colitis” to a disease that was less understood then and perhaps even lesser understood today. It is likely that several clinically similar diseases may have been considered under this term. Thus it has been suggested that in 1745 Prince Charles, the Young Pretender to the throne, cured himself of ulcerative colitis by adopting a milk-free diet!2,4 Excellent descriptions have been provided by the Surgeon General of the Union Army (describing the medical history of the American Civil War), Wilks & Moxon (1875), Allchin (1885) and Hale-White (1888). By 1909, around 300 cases were collected from various London hospitals and described at a symposium of the Royal Society of Medicine.2 Ulcerative colitis has been defined as an inflammatory disease of unknown origin, characterized clinically by recurrent attacks of bloody diarrhea, and pathologically by a diffuse inflammation of the wall of the large bowel. The inflammatory changes spread proximally from the rectum; and are confined to (or most severe in) the colonic and rectal mucosa.2 Nevertheless at one time it was suggested that an accurate definition is not possible since the etiology is largely unknown.5 Whether this is true even today is a matter of personal opinion. To match the definition, it appears that the diagnosis of ulcerative colitis follows a unique rule. Unlike several conditions, the final diagnosis of ulcerative colitis is anything but histological! The histological features of chronic colitis may be present as early as 1 week after the onset of clinical symptoms; are usually well established after 3–4 weeks time; and are relatively non- specific (several other colitis such as infective, ischemic, drug induced or toxic, apart from Crohn’s disease show similar features). Hence, in routine practice, clinical, imaging and conventional sigmoidoscopic and colonoscopic features are correlated to arrive at a diagnosis. The accuracy of individual methods of diagnosis is difficult to determine since very few studies have looked into these aspects critically. However, in one study the performance of clinical impression in recognizing disease activity, as determined by endoscopy, was relatively poor (sensitivity = 56.0%, negative predictive value = 56.8%, kappa coefficient = 0.35) while © Tropical Gastroenterology 2011 88 Tropical Gastroenterology 2011;32(2):87–93 histological evaluation in recognizing disease activity was limited sample at a single point in time. One of the reasons for markedly better (sensitivity = 93.5%, negative predictive value problems is the over-zealous diagnosis of ulcerative colitis, = 89.1%, kappa coefficient = 0.70).6 Conventionally, endoscopy based on a single rectal biopsy that contains some crypt (sigmoidoscopy and colonoscopy) is considered an extension, abscesses. Crypt abscesses are seen in both acute and chronic if not a part of clinical examination, especially if the evaluating colitis including Crohn’s disease, bacterial infection, physician is a gastroenterologist. Thus endoscopy has a lymphocytic colitis and Clostridium difficile-related toxic special role in the diagnosis of ulcerative colitis. Several damage. In bacterial infection crypt abscesses are superficial.18 endoscopic activity grading schemes are available (Matts, The differential diagnosis can be narrowed down with help of Schroeder or Mayo, Baron, Blackstone, Rashmilewitz and their a history of long duration (typically of bloody diarrhea over six modifications).7 Endoscopy alone may not be able to provide a month duration). Thus a properly filled requisition form specific diagnosis in nearly 70% of cases especially if non- accompanying the specimen is invaluable. Histological features specific features such as only hyperemia or aphthous ulcers of chronicity include crypt branching and Paneth cell are observed.8 However once a diagnosis is rendered there is metaplasia. Of the two, crypt branching is more reliable a fairly acceptable concordance between endoscopic and especially if the branches are at irregular angles and parallel to histological assessment of activity.9 In general, endoscopic the muscularis mucosae. It is worth noting that since Paneth assessments and agreements are better with training and cells may extend into the proximal colon in adults and some experience.7,10,11 To enhance the accuracy of diagnosis, several distance further in pediatric patients, their presence in non-invasive methods have been introduced over the years. rectosigmoid biopsies is excellent proof of chronic damage. Most of these are of use in differentiating Crohn’s disease and Thus biopsies must be submitted properly labeled with regard ulcerative colitis or in assessing activity of illness in diagnosed to their site and not aggregated together in one specimen bottle ulcerative colitis.12-15 Here, mention needs to be made that or submitted unlabeled. Inflammation is typically imaging techniques are gradually gaining a place in lymphoplasmacytic, confined to the lamina propria, extends complementing other non-invasive and endoscopic methods throughout its thickness with relative sparing of the intercryptal of diagnosis. However, their role in differentiating Crohn’s surface epithelium. In bacterial colitis the inflammation is not disease from ulcerative colitis appears more appropriate by uniform,19 whereas in lymphocytic colitis and collagenous virtue of detecting small intestinal involvement than colitis the inflammation is usually limited to the top half of the demonstrating specific diagnostic features of ulcerative lamina propria (“top heavy”). The intercryptal surface colitis.13,16 epithelium is damaged in ischemic damage, C. difficile toxin, Despite acceptance of the consensus that ulcerative colitis and lymphocytic and collagenous colitis. The muscularis should be diagnosed after a reasonable collation and mucosa is often thickened in inflammatory bowel disease. In assessment of clinical, endoscopic, imaging and histological addition, in collagenous colitis there is a thick, irregular collagen data; due to various reasons and limitations reliance on one or band under this surface epithelium.20 Lymphocytic and more observations is resorted to. Thus, for obvious reasons, collagenous colitis are important because they can produce the diagnosis of acute severe ulcerative colitis that has an chronicity similar to inflammatory bowel disease, although there immense bearing on immediate and critical management are clinical and endoscopic differences. Granulomatous decisions is based purely on clinical and laboratory data.17 inflammation undoubtedly points to Crohn’s disease (and Even if such special situations are excluded, more often than wherever relevant to tuberculosis). Granulomas may not, there is an undue reliance on histological features, perhaps occasionally be found as a reaction to mucin extruded from as a tribute to the traditional method of final diagnosis whenever crypt abscesses (“crypt granulomas”). It must be emphasized a tissue sample is available. Thus, as discussed in a recent that there may be instances wherein unusual findings are excellent review,18 endoscopic biopsies play a major role in the present. The article by Shah et al in this issue1 lists unusual establishment of a diagnosis of idiopathic inflammatory bowel histological features that include a predominance of disease despite the fact that it is clearly not possible to be polymorphs in 38% and eosinophils in 6.3% cases. Such consistently certain of the presence of inflammatory bowel observations have been recorded in both inflammatory bowel disease (as opposed to infection, toxin, and the like) on a single disease and infective colitis. A recent interesting report Ulcerative colitis 89 reiterates that such findings are associated with active colitis.21 Despite similarities with other conditions, one of the time- Histological changes in ulcerative colitis can be graded similar tested characteristic that assists in the diagnosis ulcerative to clinical features.22 colitis is a diffuse continuous involvement of the colon. Therefore, communication between the attending