The Histology-Driven Differential Diagnosis in Bowel Inflammatory Conditions Is Not All That Obvious: Evidence from a Survey Based on Digital Slides

(1) Background: when the pathologist faces histologic slides from colonoscopies in daily practice, given the large number of entities and etiologies under inflammatory bowel conditions, in-depth definition of the histological spectrum and the recommendations of current guidelines are often not enough to conclusively define a diagnostic framework. Histological patterns should be organized hierarchically in flowcharts that consider the correlation with clinical data. We conducted an online survey asking a group of gastroenteropathologists to apply a pattern classification based on the most significant lesions in colitis differential diagnosis: crypt distortion and activity. (2) Methods: digital slides from 20 endoscopy samples were analyzed by twenty pathologists and classified according to the occurrence of crypt distortion (nondestructive-destructive colitis) and subsequently to the evidence of activity (ND1-2-3, D1-2). (3) Results: in 8 out of 20 (40%) cases, the participants reached a full agreement regarding the evaluation of crypt distortion (5 cases: nondestructive colitis; 3 cases: destructive colitis). The calculated agreement was k = 0.432. In the second-level quiz (ND1-2-3 and D1-2), full agreement between participants was achieved for 7 of the 28 (25%) possible classifications, with k = 0.229. (4) Conclusions: The findings from this survey are indicative of an unexpectedly low consensus, even among dedicated pathologists, about the recognition of histological changes that are commonly considered critical lesions in the histologic identification of bowel non-neoplastic diseases. In our opinion, these divergences imply a significant risk of misdiagnosis of bowel inflammatory conditions, hampering the usefulness of histological assessment.

Modern Approaches to the Diagnosis and treatment of <i>Clostridioides difficile (C. difficile)</i>-associated Disease in Adults (literature Review and Expert Council Resolution)

Aim: to review the modern approaches to the diagnosis and treatment ofC. difficile-associated disease in adults and present the resolution of the Expert Council held on March 25, 2023 in Moscow.

General provisions.C. difficileis the most important nosocomial pathogen which spores are also commonly found in the environment. Microbiota impairment, primarily due to the use of antibacterial drugs, is a key stage in the development ofC. difficile-associated disease. A search for an infection should be carried out only in patients with diarrhea, and it is advisable to use at least 2 laboratory methods. The drug of choice for first-line treatment is vancomycin. If drug treatment is ineffective or the patient has recurrent clostridial infection, fecal microbiota transplantation should be considered. The probiotic strainSaccharomyces boulardii CNCM I-745has a direct inhibitory effect onC. difficiletoxin A, promotes normalization of the intestinal microbiota composition, and decreases the inflammatory reaction in colonic mucosa colonized with a toxigenic strain ofC. difficile.

Conclusions. Addition of the probiotic strainSaccharomyces boulardii CNCM I-745to antibacterial therapy promotes both primary and secondary prevention ofC. difficile-associated disease.

Automated histological classification for digital pathology images of colonoscopy specimen via deep learning

Colonoscopy is an effective tool to detect colorectal lesions and needs the support of pathological diagnosis. This study aimed to develop and validate deep learning models that automatically classify digital pathology images of colon lesions obtained from colonoscopy-related specimen. Histopathological slides of colonoscopic biopsy or resection specimens were collected and grouped into six classes by disease category: adenocarcinoma, tubular adenoma (TA), traditional serrated adenoma (TSA), sessile serrated adenoma (SSA), hyperplastic polyp (HP), and non-specific lesions. Digital photographs were taken of each pathological slide to fine-tune two pre-trained convolutional neural networks, and the model performances were evaluated. A total of 1865 images were included from 703 patients, of which 10% were used as a test dataset. For six-class classification, the mean diagnostic accuracy was 97.3% (95% confidence interval [CI], 96.0–98.6%) by DenseNet-161 and 95.9% (95% CI 94.1–97.7%) by EfficientNet-B7. The per-class area under the receiver operating characteristic curve (AUC) was highest for adenocarcinoma (1.000; 95% CI 0.999–1.000) by DenseNet-161 and TSA (1.000; 95% CI 1.000–1.000) by EfficientNet-B7. The lowest per-class AUCs were still excellent: 0.991 (95% CI 0.983–0.999) for HP by DenseNet-161 and 0.995 for SSA (95% CI 0.992–0.998) by EfficientNet-B7. Deep learning models achieved excellent performances for discriminating adenocarcinoma from non-adenocarcinoma lesions with an AUC of 0.995 or 0.998. The pathognomonic area for each class was appropriately highlighted in digital images by saliency map, particularly focusing epithelial lesions. Deep learning models might be a useful tool to help the diagnosis for pathologic slides of colonoscopy-related specimens.

Co-existing sickle cell anaemia and inflammatory bowel disease: case report and review of the literature

Sickle cell anaemia (SCA) is a chronic haemolytic anaemia associated with vaso-occlusive painful crises which may affect several systems including the gastro-intestinal system, resulting in abdominal pain. The concurrence of inflammatory bowel disease and haemoglobinopathy is rare. No previously reported concurrent cases of both SCA and ulcerative colitis (UC) in sub-Saharan Africa were found in the literature. A 16-year-old girl with concurrent SCA and UC is presented. She was admitted to University College Hospital, Ibadan with a 1-year history of recurrent peri-umbilical pain and bloody stools. These symptoms were mainly attributed to SCA at the referring hospital, and she was managed for chronic tropical diarrhoea without a remarkable clinical response. This case illustrates the concurrent presentation of SCA and ulcerative colitis which led to the missed and delayed diagnosis of ulcerative colitis.

Colonoscopic image synthesis with generative adversarial network for enhanced detection of sessile serrated lesions using convolutional neural network

Computer-aided detection (CADe) systems have been actively researched for polyp detection in colonoscopy. To be an effective system, it is important to detect additional polyps that may be easily missed by endoscopists. Sessile serrated lesions (SSLs) are a precursor to colorectal cancer with a relatively higher miss rate, owing to their flat and subtle morphology. Colonoscopy CADe systems could help endoscopists; however, the current systems exhibit a very low performance for detecting SSLs. We propose a polyp detection system that reflects the morphological characteristics of SSLs to detect unrecognized or easily missed polyps. To develop a well-trained system with imbalanced polyp data, a generative adversarial network (GAN) was used to synthesize high-resolution whole endoscopic images, including SSL. Quantitative and qualitative evaluations on GAN-synthesized images ensure that synthetic images are realistic and include SSL endoscopic features. Moreover, traditional augmentation methods were used to compare the efficacy of the GAN augmentation method. The CADe system augmented with GAN synthesized images showed a 17.5% improvement in sensitivity on SSLs. Consequently, we verified the potential of the GAN to synthesize high-resolution images with endoscopic features and the proposed system was found to be effective in detecting easily missed polyps during a colonoscopy.

Prediction of severity and outcomes of colon ischaemia using a novel prognostic model: a clinical multicenter study

OBJECTIVE

To identify risk factors of disease severity and between mild and severe colon ischaemia (CI) patients and to improve clinical outcomes, this study aimed to explore a novel scoring model.

METHODS

Retrospective analyses of hospital records between January 2009 and December 2019 were included. Clinical manifestations, mortality, Oakland score, laboratory tests, colonoscopy, and histopathology were collected. Risk factors of severe CI were determined by univariate and multivariate logistic regression and used for the predicting model.

RESULTS

A total of 203 patients with CI were included. Serum C-reactive protein (CRP) and albumin ratio (CAR) were much higher in the severe CI group compared with that of the mild CI group (3.33 ± 1.78 versus 0.68 ± 0.97, p < .001). The Oakland score was much higher in the severe CI group (12.00 ± 3.02 versus 8.77 ± 1.63, p < .001). The histopathological finding of fibrin thrombi was an independent risk factor that predicted poor outcomes (20.00% versus. 1.09%, p < .001). Patients present with CAR ≥3.33, Oakland score ≥12, and histopathological fibrin thrombi were independent risk factors. In addition, the final scoring model was 0.042 × Oakland score + 1.040 × CAR + 3.412 × fibrin thrombi, the area under the curve (AUC) was 0.960 (95% confidence interval:0.930-0.990), and the sensitivity and specificity of the novel scoring model were 95% and 92%, respectively.

CONCLUSIONS

The novel prognostic model was established to predict CI severity and clinical outcomes efficiently.Key messagesIn this article, we discuss the scoring model for clinical outcomes of colon ischaemia patients.In our study, the sensitivity and specificity of a novel scoring model are very high.Thus, laboratory tests (CRP albumin ratio), Oakland score, and histopathological findings (fibrin thrombi) can be assessed efficiently for colon ischaemia outcomes.

Histopathology of non-IBD colitis practical recommendations from pathologists of IG-IBD Group

Pathologists are often called upon to diagnose colitides that differ from the two main forms of inflammatory bowel disease (IBD). These non-IBD colitides include infectious colitis, microscopic colitis, ischemic colitis, eosinophilic colitis, autoimmune enterocolitis, segmental colitis associated with diverticulosis, drug-induced colitis, radiation colitis and diversion colitis. The diagnosis of these different disease entities relies on the histopathological examination of endoscopic biopsies of the gastrointestinal tract. This paper reviews the main histomorphological characteristics of the various Non-IBD colitides.

Clinical significance of pathologic abnormalities in biopsy samples from the appendiceal orifice

AIMS

Appendiceal orifice mucosa often appears inflamed endoscopically, even when other colonic segments appear normal. Histological findings in biopsy samples taken from endoscopically abnormal mucosa may simulate a variety of inflammatory colitides. We performed this study to evaluate the clinical implications of inflammatory changes isolated to the appendiceal orifice.

METHODS AND RESULTS

In this double cohort study, biopsy samples from 26 histologically abnormal appendiceal orifices were reviewed. Twenty-five control cases were culled from endoscopically normal (n = 11) and abnormal (n = 14) appendiceal orifices that were histologically normal. Histological findings were correlated with presentation, medication history, findings at other colonic sites and clinical outcomes. Study cases displayed active inflammation (n = 12), chronic active inflammation (n = 13) or features simulating collagenous colitis (n = 1). Eighteen patients had biopsies taken from other colonic sites; these revealed benign polyps (n = 10) or displayed active (n = 4) or chronic active (n = 4) inflammation. All patients with findings isolated to the appendiceal orifice were asymptomatic at most recent clinical follow-up. Four of eight (50%) of the patients with inflammation in other biopsy samples were ultimately diagnosed with ulcerative colitis, in keeping with the well-established role of the appendix as a 'skip lesion' in that disorder. Control patients presented for screening colonoscopy (n = 19), iron deficiency anaemia (n = 3) or change in bowel habits (n = 3) and none reported gastrointestinal symptoms upon follow-up, regardless of the endoscopic appearance of the appendiceal orifice.

CONCLUSION

Isolated inflammation of the appendiceal orifice mucosa should not be regarded as a feature of evolving inflammatory bowel disease or other types of chronic colitis.

Etiology and surgical management of pediatric acute colon perforation beyond the neonatal stage

PURPOSE

Acute colon perforation is a pediatric surgical emergency. We aimed to analyze the different etiologies and clinical characteristics of acute non-traumatic colon perforation beyond the neonatal period and to identify surgical management and outcomes.

METHODS

This retrospective study included 18 patients admitted with acute colon perforation and who received surgical treatment.

RESULTS

Age of patients ranged between 1 month and 15 years. Five patients swallowed foreign objects (two swallowed magnets), two had colon perforation secondary to a malignant tumor (both colorectal adenocarcinoma) and two were iatrogenic (one prior colonoscopy, one air enema for intussusception). There was one perforation due to chemotherapy and Amyand's hernia respectively. The remaining seven patients had unknown etiologies; five of them were diagnosed with colitis. Fifteen (83.3 %) patients underwent open laparotomy, among which four attempted laparoscopy first. Three (16.7 %) patients underwent laparoscopic surgery. Fourteen (77.8 %) patients received simple suture repairs and four (22.2 %) received colonic resections and anastomosis. Four (22.2 %) patients received a protective diverting colostomy and three (16.7 %) received an ileostomy.

CONCLUSIONS

There is a wide range of etiology besides necrotizing enterocolitis and trauma, but a significant portion of children present with unknown etiology. Type of surgery elected should be dependent on the patient's etiology, disease severity and experience of surgeons.

Multisystem Inflammatory Syndrome in Children Associated With Severe Acute Respiratory Syndrome Coronavirus-2 in an 8-Week-Old Infant

We describe an 8-week-old infant with severe gastrointestinal symptoms, significant hypoalbuminemia, and mild carditis following asymptomatic infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The infant's symptoms, including their temporal appearance, were consistent with multisystem inflammatory syndrome in children (MIS-C). A unique finding on colonic histology which may shed light on the pathogenesis of MIS-C was identified. The patient improved significantly following several anti-inflammatory treatments. The lag between the presentation of MIS-C and initial SARS-CoV-2 exposure, which may often be asymptomatic, together with the young age of our patient, makes this a challenging diagnosis. Clinicians should be aware of this entity, even in the neonatal and infantile age groups, to facilitate timely identification and treatment.

Non-neoplastic colorectal disease biopsies: evaluation and differential diagnosis

A wide variety of non-neoplastic conditions may be encountered on colorectal biopsy encompassing idiopathic, infectious, vascular and immune-mediated aetiologies. Although interpretation of such biopsies may be challenging, appreciation of the dominant pattern of injury and subsequent host response may allow for a more focused histological diagnosis in the correct clinical and endoscopic setting. This article aims to provide a systematic, methodical approach to the assessment of such biopsies, concentrating mainly on diagnoses other than inflammatory bowel disease.

Mesenteric Arteriovenous Dysplasia/Vasculopathy Mimicking Crohn's Disease: A Case Report

Mesenteric arteriovenous vasculopathy (MAVD/V) is an extremely rare and poorly understood disease and its incidence is probably underestimated. It is an uncommon, non-inflammatory and non-atherosclerotic form of mesenteric vascular injury, first reported in 2016, with characteristic histopathologic evidence of fibromuscular dysplasia-like vascular changes. We present the case of a chronically ill 84-year-old female with a 5 year history of recurrent small bowel obstruction, who underwent segmental resection of the small bowel. Intraoperative examination showed bowel stricture with fibrosis, intraluminal pill fragments and creeping mesenteric adipose tissue clinically compatible with Crohn's disease. Histological examination showed acute and chronic mucosal injury characterized by crypt distortion, ulcerations with granulation tissue, pseudo-pyloric metaplasia, areas of fibrosis and serosal adhesions. Multiple blood vessels (including both veins and arteries) demonstrated wall hyalinization, elastic degeneration and non-atherosclerotic luminal occlusion. The pattern of the mucosal injury is, in this case, potentially a consequence of acute and chronic ischemic processes secondary to mesenteric arteriovenous vasculopathy.

Ileocolic anastomotic inflammation after resection for Crohn's disease indicates disease recurrence: a histopathologic study

Objectives: We performed a pathological pilot study to characterize the inflammation at the ileocolic anastomosis as Crohn's disease or ischemia.Methods and materials: Subjects were selected at random from a retrospective database of patients with Crohn's disease and who had undergone an ileocolic resection with subsequent endoscopic assessment of the anastomosis and neo-terminal ileum. Pathology slides from the anastomotic mucosa, either from targeted biopsies or subsequent ileocolic resections, were re-assessed histologically for features of ischemia and of Crohn's disease.Results: Twenty-nine specimens from 8 patients were reviewed, including 12 ileocolic resection specimens and 17 sets of endoscopic biopsies. Twenty-seven of the 29 specimens, accounting for all of the patients, had evidence of CD-like features. In contrast, only 2 specimens, accounting for 2 of 8 patients, had histologic features of ischemia, and both specimens also had Crohn's-like features.Conclusion: To our knowledge this is the first study to specifically evaluate the pathology of ileocolic anastomoses in Crohn's disease. It suggests that anastomotic inflammation is predominantly a manifestation of recurrent Crohn's disease rather than of postoperative ischemia.

Histopathological Mimics of Inflammatory Bowel Disease

This review article discusses the challenges of making a firm histopathological diagnosis of inflammatory bowel disease (IBD) on biopsy and resection material and the importance of its distinction from a range of other inflammatory and infective conditions that may closely mimic IBD. In many cases, the diagnosis of ulcerative colitis or Crohn's disease is straightforward, especially when patients have a typical presentation and characteristic histopathological features. Knowledge of the full clinical history is very important, particularly past and recent medical history, drug history, foreign travel, or known contact with individuals with specific infection. Discussion of all cases of suspected IBD within a multidisciplinary team meeting is required to ensure that clinical, radiological, and pathological features can be correlated. Mimics of IBD can be divided into 4 categories: 1) those due to specific infection, 2) those due to a specific localized inflammatory process, 3) those due to iatrogenic causes, and 4) other rarer causes. Accurate diagnosis of IBD and exclusion of these mimics are crucial for patient management. Once a diagnosis of IBD has been proffered by a pathologist, it is very difficult to "undiagnose" the condition when an alternative diagnosis or "mimic" has been subsequently identified. The histological diagnosis of each of these IBD mimics is discussed in detail, with guidance on how to avoid the pitfall of missing these sometimes very subtle and "difficult to diagnose" conditions.

Histopathologic Patterns of Colitis in Patients With Impaired Renal Function

OBJECTIVES

To characterize the histopathologic features of colitis in patients with impaired renal function.

METHODS

We retrospectively identified 413 patients who underwent colonoscopic evaluation for colitis between 2011 and 2015. Patients were divided into four groups based on estimated glomerular filtrate rates. Patients with impaired renal function were compared to overall and age-matched patients with normal renal function.

RESULTS

Compared to a preponderance of inflammatory bowel disease (33%) and lymphocytic colitis (9.6%) in patients with normal renal function, ischemic colitis (58%) was the predominant histopathologic pattern in the patients with impaired renal function. Infectious colitis was the second most common pattern (20.8%), with Clostridium difficile and cytomegalovirus infections being more frequent. Medication-induced injury was the third most common pattern, with crystal-associated injury being the exclusive pattern found in this study.

CONCLUSIONS

Colitis in patients with impaired renal function is etiologically distinct from that seen in patients with normal renal function.

Correlation between histological findings and endoscopic findings in patients with ulcerative colitis: Basal plasmacytosis is an important finding suggesting active inflammation

AIMS

In clinical practice, patients of ulcerative colitis showing divergence between the histological findings and endoscopic findings are often encountered. Therefore, we compared histological findings with endoscopic findings, indicating the severity of the inflammation of ulcerative colitis.

METHODS AND RESULTS

The study group comprised 191 patients (527 biopsy specimens) with ulcerative colitis who underwent lower gastrointestinal endoscopy with biopsy in our hospital from July 2015 to June 2016. Endoscopic findings of the mucosa at the biopsy site were classified into seven levels according to the severity of inflammation: noninflamed mucosa, red signs, loss of visible vascular patterns, granular mucosa, friable mucosa, spontaneous bleeding, and erosions/ulcers (E/U). All biopsy samples were examined for the presence or absence of five histological findings (basal plasmacytosis [BP], neutrophil infiltration, cryptitis, crypt abscess [CAb], and E/U), and the results were contrasted with endoscopic findings. The 191 patients comprised 123 (64.4%) males and 68 (35.6%) females, with a median age of 47 years (range, 8-82). Among the 527 specimens, the detection rates of BP, CAb, and E/U in mucosa with endoscopic E/U were 58.5, 27.4, and 18.3%. The detection rate of BP in mucosa with red signs was 22.4%; in mucosa, with loss of visible vascular patterns, it was 16.9%; in granular mucosa, it was 35.7%, and in mucosa with E/U, it was 58.5%. BP was frequently seen in severely inflamed mucosa associated with E/U on endoscopic examination.

CONCLUSION

BP was considered an important finding, suggesting the presence of active and severe inflammation.

Microscopic colitis: a population-based case series over a 9-year period in Northern Ireland

AIM

We report clinicopathological experience of microscopic colitis (MC) in a population-based case series in Northern Ireland over a 9-year period.

METHOD

The pathology laboratory information system within a large teaching centre serving two healthcare trusts was interrogated for cases coded between 2008 and 2016 as collagenous colitis (CC) or lymphocytic colitis (LC). Demographic, clinical and follow-up information was collected from healthcare records.

RESULTS

A total of 326 new diagnoses of MC were identified, an average annual incidence of 6.7 per 100 000 population. The average annual incidence of CC and LC was 5.0 and 1.7 per 100 000 population, respectively. For coding reasons it is likely that LC data are incomplete. Of 191 cases diagnosed by specialist gastrointestinal pathologists, 141 patients had CC and 50 patients had LC. Both CC and LC predominantly involved women aged 60-79. Some 15% demonstrated endoscopic abnormalities. Endoscopic sampling protocols varied widely: 30% of individuals with CC and 32% of those with LC had the right and left colon sampled separately, with histology concordant in 95% of cases. Of the 191 cases, only one case (of LC) was refractory to treatment; the rest exhibited a clinical response. Only 35 patients had follow-up endoscopy and biopsies, and three of each diagnosis showed persistent disease on histology.

CONCLUSION

Overall, CC and LC are benign conditions with similar demographics, clinical associations, management and outcomes. Separate sampling of the right and left colon is advised at colonoscopy if this diagnosis is being considered, but left colonic sampling, which can be performed at flexible sigmoidoscopy, will diagnose the vast majority of cases.

Atypical cause of intractable diarrhea in a hemodialysis patient, masked by Clostridium difficile-associated diarrhea and ischemic colitis: a case report

Background

Patients with end-stage kidney disease (ESKD) most commonly complain of gastrointestinal symptoms, such as diarrhea. Diarrhea negatively affects patient quality of life and has miscellaneous etiologies, such as Clostridium difficile-associated diarrhea (CDAD) and ischemic colitis. However, it is sometimes extremely difficult to determine the true etiology given the comorbidities and complications the patients have. A rare cause of diarrhea is ulcerative colitis (UC), which commonly affects the rectum and proximal colon in a continuous fashion. UC with rectal sparing or segmental distribution, although atypical, sometimes leads to misdiagnosis. Herein, we present a case of UC in a patient on hemodialysis with intractable diarrhea; we initially considered that the diarrhea was caused by CDAD and ischemic colitis.

Case presentation

A 69-year-old man with a history of hypertension, bilateral thalamic hemorrhage, and decreased kidney function was admitted to our hospital because of congestive heart failure. Volume control was impossible due to renal dysfunction and he was started on hemodialysis. Thereafter, he received various antibiotics for bacterial infections. Simultaneously, he experienced continuous watery, and sometimes bloody, diarrhea, which was diagnosed as CDAD owing to a positive stool test for Clostridium difficile toxins. Antibiotic treatment for CDAD did not result in symptom relief. Subsequently, we performed colon biopsy via colonoscopy, and the pathology showed virtually no inflammation with rectal sparing and segmental distributions. These findings favored the presence of ischemic colitis due to arteriosclerosis and ESKD rather than infections. He died of cardiac arrest before the diarrhea was alleviated. Finally, UC was revealed on autopsy as the main cause of the uncontrollable diarrhea.

Conclusions

Patients with ESKD have a greater risk of developing CDAD and ischemic colitis, which have clinical features that sometimes overlap with those of UC, as in the present case. This case emphasizes the importance of correctly diagnosing the etiology of intractable diarrhea and the fact that other diarrhea etiologies can obscure the existence of inflammatory bowel disease, which should be considered and treated properly when patients on hemodialysis present with intractable diarrhea.

Isolated Acute Terminal Ileitis Without Preexisting Inflammatory Bowel Disease Rarely Progresses to Crohn's Disease

BACKGROUND

Isolated acute terminal ileitis without chronic features of inflammation poses a diagnostic challenge. Few studies have investigated the clinical significance of this entity in patients without history of inflammatory bowel disease.

AIMS

We sought to elucidate the long-term prognosis of patients with isolated acute terminal ileitis, its rate of progression to Crohn's disease, and the factors associated with terminal ileitis development to Crohn's disease.

METHODS

Retrospective review of clinical, endoscopic, and radiographic records was performed on 108 patients with histologic evidence of isolated acute terminal ileitis on terminal ileal biopsies obtained by diagnostic ileocolonoscopy performed between January 1, 2002, and December 31, 2014, at the Mayo Clinic. Statistical analysis was performed with Student's t test and Fisher's exact test to identify the factors associated with the progression of isolated acute terminal ileitis to Crohn's disease.

RESULTS

The median follow-up time across 108 patients was 54.7 months (interquartile range 32.0-89.0 months). Five patients (4.6%) developed Crohn's disease after a median of 32.3 months (7.5-43.2 months). The presence of narrowing/stricturing (p = 0.03) on abdominal cross-sectional imaging at the time of terminal ileitis diagnosis was correlated with eventual Crohn's disease development. No significant correlation was found with clinical symptoms, endoscopic features, laboratory testing, NSAID use, smoking history, or family history of inflammatory bowel disease.

CONCLUSIONS

Isolated acute terminal ileitis discovered on diagnostic ileocolonoscopy rarely develops to Crohn's disease. Presence of stricturing/narrowing on cross-sectional imaging may predict eventual Crohn's disease development.

Ischaemic colitis: uncertainty in diagnosis, pathophysiology and management

Ischaemic colitis is the most common form of gastrointestinal ischaemia, but may be confused with acute mesenteric ischaemia, inflammatory bowel disease or infectious colitis. This review article outlines the current classification, epidemiology and risk factors, as well as approaches about diagnosis and management to guide clinical practice. It also identifies areas for further research.

Clinical Aspects of Idiopathic Inflammatory Bowel Disease: A Review for Pathologists

CONTEXT

-Idiopathic inflammatory bowel disease manifests with different clinical phenotypes showing varying behavior and risk for neoplasia. The clinical questions that are posed to pathologists differ depending on phase of the disease and the clinical circumstances. Understanding the clinical aspects of the dynamic disease process will enhance the role of pathology in optimizing the care of patients with inflammatory bowel disease.

OBJECTIVE

-To review clinical and surgical aspects of inflammatory bowel disease that are relevant to practicing pathologists.

DATA SOURCES

-The literature was reviewed.

CONCLUSIONS

-Diagnosis and management of inflammatory bowel disease require an integrated evaluation of clinical, endoscopic, radiologic, and pathologic features. Therefore, close interaction between clinicians and pathologists is crucial. Having this team approach improves understanding of the pertinent clinical and surgical aspects of the disease and assists in the recognition of unusual presentation of variants, as well as mimics of idiopathic inflammatory bowel disease, by pathologists.

Post Colonoscopy Ischaemic Colitis in a Patient without Risk Factors for Colon Ischemia: A Case Report

Ischaemic colitis is the most common form of intestinal ischaemia and is more common in the elderly and in the people having risk factors for colonic ischaemia. Colonoscopy procedure itself is a rare cause of ischaemic colitis. Fewer than 20 cases of ischaemic colitis caused by colonoscopy procedure have been reported in the english literature till date. This patient presented to us within hours of routine colonoscopy with rectal bleeding and lower abdominal pain. On repeat colonoscopy, the patient had mucosal oedema and ulcerations in the descending colon and sigmoid colon. Computed tomography of abdomen and biopsy of the involved segment confirmed ischaemic colitis. The patient recovered with conservative management.

Crystal-Associated Colitis with Ulceration Leading to Hematochezia and Abdominal Pain

Lower GI bleeding is a common cause for hospitalization in adults. Medication-associated mucosal injury is an important clinical entity that can result in significant morbidity and mortality. We present the case of a 45-year-old woman with a 3-month history of intermittent abdominal cramping and rectal bleeding. Her medical history was extensive and included end-stage renal disease and a remote history of endometrial carcinoma that was treated with radiation. Initial workup was concerning for ischemic and radiation colitis, however, histology was most consistent with acute inflammation and ulceration associated with crystal fragments. Sevelamer and cholestyramine are commonly used ion-exchange resins that have been associated with mucosal damage. Both medications were discontinued and her symptoms resolved. Our case highlights an underrecognized but important cause of hematochezia.

Late-onset colitis after cord blood transplantation is consistent with graft-versus-host disease: results of a blinded histopathological review

Cord colitis syndrome after umbilical cord blood transplantation (UCBT) involves late-onset diarrhea, absence of infection or GVHD, chronic active colitis, and granulomatous inflammation that responds to antibiotics. We tested the hypothesis that Seattle recipients of UCBT had late-occurring colitis distinct from GVHD and colitis in other allograft recipients. We conducted a blinded histological review of 153 colon biopsy specimens from 45 UCBT recipients and 45 matched allografted controls obtained between day +70 and day +365 post-transplantation. Diarrhea was the primary indication for biopsy in 10 UCBT recipients and 11 controls. No histological differences were seen between UCBT recipients and controls with diarrhea or between the entire cohort of UCBT recipients and their controls. Distorted mucosal architecture and apoptotic crypt cells typical of GVHD were common in both groups; Paneth cell metaplasia and granulomas were rare findings. Chronic active colitis was present in 58% of the UCBT recipients and in 62% of controls. No UCBT recipient with diarrhea was treated with antibiotics, and all recipients responded to systemic corticosteroids. Colitis occurring after day +70 in allografted controls was related to acute GVHD, independent of the source of donor cells. We could not identify a histologically distinct cord colitis syndrome in either the UCBT or the non-cord blood allograft recipients.

The association between circulating high-sensitivity C-reactive protein concentration and pathologic measures of colonic inflammation

PURPOSE

C-reactive protein (CRP), an inflammation marker, is associated with colorectal cancer (CRC) risk in some prospective studies. Whether increased CRP is indicative of colonic inflammation, a possible CRC cause, or of other sources of inflammation (e.g., adiposity), is unknown. Thus, we evaluated the association between CRP and colonic mucosal measures of inflammation.

METHODS

151 adults undergoing colonoscopy provided a blood sample and random left- and right-side colonic mucosal biopsies. Height and weight were measured, and lifestyle information was collected. High-sensitivity C-reactive protein (hsCRP) was measured by immunoturbidometric assay. A gastrointestinal pathologist evaluated biopsies for seven colonic inflammation measures. Of 119 participants with complete information, 24 had an inflammatory bowel disease (IBD) history and were analyzed separately. We calculated the number of colonic inflammation measures present in both biopsies, and separately for right and left biopsies. Adjusted geometric mean hsCRP was calculated using linear regression, overall, by demographic and lifestyle factors, and inflammation measures.

RESULTS

Most participants had ≥ 1 colonic inflammation measure (0: 21 %, 1: 39 %, ≥ 2: 40 %). Adjusted mean hsCRP did not increase with increasing number of inflammation measures (0: 1.67; 1: 1.33; ≥ 2: 1.01 mg/L; p trend = 0.21). Obese (2.03 mg/L) and overweight (1.61 mg/L) participants had higher adjusted mean hsCRP than normal-weight participants (0.62 mg/L; p trend <0.0001). Patterns were similar for participants with a history of IBD.

CONCLUSIONS

hsCRP concentration was not associated with colonic inflammation, although hsCRP increased with adiposity. The hsCRP-CRC association may be explained by residual confounding by other risk factors, such as adiposity, rather than by CRP marking colonic inflammation.

A review of ischemic colitis: is our clinical recognition and management adequate?

Ischemic colitis is a common cause of hospital admissions; however it is frequently confused intellectually with mesenteric ischemia and often misdiagnosed as infectious diarrhea or Clostridium difficile colitis. Ischemic colitis is caused by non-occlusive insult to the small vessels supplying the colon without a clear precipitating factor. It is more common in females and in patients above 60 years of age. The classic presentation includes sudden onset of lower abdominal pain followed by the urge to defecate and bloody diarrhea. Focal right-sided ischemic colitis has more pain and a worse prognosis. Choosing the correct diagnostic studies is challenging and requires proficient knowledge of the disease. Management is usually conservative, however around 10-20% of the patients will require surgery. Acute ischemic colitis usually resolves; nevertheless some patients may develop chronic segmental colitis or a stricture. One ischemic colitis caveat is that it may be the first sign of undiagnosed cardiac disease. A firm grasp on this common yet little discussed condition is valuable to a gastrointestinal consultant and hospitalist alike.

Life-long learning and self-assessment

New Frontiers in Pathology is a unique educational event intended to meet the ongoing educational needs of practicing pathologists. Continuous medical education (CME) is required for maintenance of licensure by virtually all state licensing bodies. Satisfying CME requirements hinges on earning a minimum number of American Medical Association Physician Recognition Award category 1 credits through various activities, including courses like New Frontiers in Pathology that are accredited by the Accreditation Council for Continuing Medical Education. Self-assessment modules (SAMs) are a key component of the American Board of Pathology expectations for maintenance of board certification. Beginning in 2006, the American Board of Pathology granted only time-limited certificates as part of an American Board of Medical Specialties-wide process for maintenance of board certification. Maintenance of board certification has requirements in 4 categories: professional standing, life-long learning and self-assessment, cognitive expertise, and evaluation of performance in practice. Life-long learning and self-assessment includes not only the traditional elements of CME but also the SAMs that are defined as educational products comprising self-administered examinations with a predetermined minimum performance level and a mechanism for receiving feedback. New Frontiers in Pathology will offer SAMs, in addition to the American Medical Association Physician Recognition Award category 1 credits, which it has been accredited to do since its inception, at its 2012 conference scheduled for August 3 through August 5 at The Homestead Resort, Michigan's largest waterfront resort on beautiful Lake Michigan.