The importance of diagnostic accuracy in colonic inflammatory bowel disease

Abstract

There is significant interobserver variation in the histological diagnosis of colonic IBD. This may have a profound effect on clinical patient care and, especially, on the choice of operation. More accurate diagnostic criteria are needed to facilitate patient care and to optimize treatment outcome.

Diagnostic Problems and Advances in Inflammatory Bowel Disease

“…In approximately 5% of IBD cases, a definite diagnosis of UC or CD cannot be established due, most commonly, to either insufficient clinical, radiologic, endoscopic or pathologic data, or because of prominent overlapping features between these two disorders (5)(6)(7)(8). Under these circumstances, the term "indeterminate" colitis (IC) has been used.…”

“…Naturally, the prevalence of establishing a "diagnosis" of IC is highly dependent on the level of awareness of the reviewing pathologist regarding the wide range of morphologic features that can be seen in IBD. For instance, in a recent study by Farmer et al, 84 IBD colectomy specimens were reviewed by 24 university pathologists and the diagnostic accuracy was compared to a single GI pathologist who has a particular interest in IBD (7). Not unexpectedly, the GI pathologist rendered a diagnosis that was different from the others in 45% of specimens, and in most cases, it resulted in a change of diagnosis from UC to CD.…”

“…Rarely, other pathologic mimics of IBD, such as NSAIDs colitis, diverticular disease-associated colitis, radiation or ischemic colitis, or infectious colitis may be interpreted as IC (4). Unfortunately, there is a strong clinical need to classify IBD patients definitively as CD or UC (or other), since an ileal pouchanal anastomosis (IPAA) "pouch" procedure is generally contradicted in CD due to a high risk of morbidity related to pouchitis, fistulas, incontinence or anastomosis leaks (6,7,11,12). In 1998, Swan et al evaluated 95 cases of "fulminant colitis" (IC) with the aim of identifying features that can help separate UC from CD (10).…”

A contemporary and critical appraisal of ‘indeterminate colitis‘

“…5,6 For instance, in an informal survey of 10 GI pathologists (unpublished data), five pathologists defined IC as ''IBD: unclear if UC or Crohn's pathologically'', three defined it as ''acute fulminant colitis (with fissures),'' and two defined it as ''IBD, unclear either clinically and pathologically.'' Of the 10 GI pathologists, 8 believed that this diagnosis should only be rendered in resection specimens, but two suggested that it can be rendered in biopsies as well, a practice that is not recommended (see below).…”

“…3,5 The frequency of establishing this diagnosis is often related to the level of awareness of the broad spectrum of pathologic features that may occur in UC and CD (see below section on causes of uncertainty in IBD pathology). For instance, in a study by Farmer et al, 6 24 university medical center pathologists from 8 institutions evaluated 84 colectomy specimens and 35 sets of biopsies from 119 consecutive patients with colonic IBD. An experienced IBD pathologist subsequently reviewed these cases without knowledge of clinical data or the patient's prior diagnosis, and rendered his own diagnosis.…”