Role of magnetic resonance imaging in diagnosis and grading of perianal fistulas

Background: Fistula-in-ano can be defined as a hollow tract or cavity which is lined by granulation tissue. In case of fistula-in-ano, one end of this fistula opens in the anal canal whereas the other end is located in perianal area. Fistula-in-ano can considerably affect quality of life of an individual because of perianal discharge of blood and pus. Imaging of these fistulas is an important part of management and MR imaging is important in assessing relationship between the fistulous tract and sphincter muscles. Moreover, MR imaging can reliably demonstrate transmural inflammation, secondary tracts/ramifications, and abscesses which cannot be diagnosed on the basis of conventional fistulography. Aims and Objectives: The aim of the study was to evaluate role of MRI in diagnosis and grading of perianal fistulae. Materials and Methods: This was a retrospective observational study, in which 60 patients with fistula-in-ano were included on the basis of a predefined inclusion and exclusion criteria. MR imaging of patients was done by 1.5 T MRI machine. Before MR imaging normal saline was injected in the fistulous tract from secondary/external opening, that is, opening around perianal area. Three plane images were obtained in all the cases. T1W, T2W, and STIR image sequences were obtained parallel to pelvic diaphragm. Coronal cuts were imaged parallel to anal canal. FAT suppressed T1W and T2W images in all cases. Type and grade of fistula were determined in all the cases. P < 0.05 was taken as statistically significant. Results: Out of total 60 patients, there were 46 (76.66%) males and 14 (23.33%) were females with a M:F ratio of 1:0.30. The mean age of male and female patients was found to be 41.93±8.96 years and 44.04±7.46 years, respectively. The most common type of fistula was found to be trans-sphincteric fistula which was seen in 31 (51.6%) cases followed by intersphencteric fistula 22 (36.6%). Extrasphincteric and suprasphincteric fistulae were relatively uncommon and were seen in 4 (6.66%) and 3 (5%) cases, respectively. MRI was accurate in diagnosis of the tract with position of internal opening and any abscess cavity or secondary tract in 23 patients. Therefore, the diagnostic accuracy of MRI was found to be 95.4%. Conclusion: MRI is an excellent tool in assessment of perianal fistula. It not only helps in precisely locating fistulous tract but also can demonstrate relationship between the fistulous tract and sphincter muscles. Moreover, it can very well demonstrate transmural inflammation, secondary tracts/ramifications, and abscesses which cannot be assessed by conventional fistulograms.

Transmural Inflammation, Ileitis, and Granulomas at the Time of Proctocolectomy in Patients with Ulcerative Colitis Do Not Predict Future Development of Pouchitis

<b><i>Background:</i></b> The most common complication following ileal pouch-anal anastomosis (IPAA) in patients with ulcerative colitis (UC) is pouchitis. Our study aimed to investigate the relationship between histopathologic findings of ileitis, granuloma, or transmural inflammation on the colectomy specimen of patients with clinically and endoscopically diagnosed UC and the development of pouchitis within the first 2 years after IPAA. <b><i>Methods:</i></b> We performed a retrospective cohort study evaluating patients undergoing colectomy with IPAA for UC between January 1, 2004 and December 31, 2016. Bivariate analyses were conducted to evaluate the relationship between clinical factors and the development of pouchitis. We performed multivariate logistic regression to evaluate the relationship between histologic, clinical, and demographic factors at the time of colectomy and subsequent development of pouchitis. <b><i>Results:</i></b> Among 626 patients, pouchitis occurred in 246 (39%). Patients with primary sclerosing cholangitis were more likely to develop pouchitis (adjusted odds ratio [aOR] 2.81, 95% confidence interval [CI] 1.02–7.72), as were patients with a family history of inflammatory bowel disease (aOR 1.75, 95% CI 1.11–2.77). Histologic findings of ileitis, granuloma, or transmural inflammation were not associated with an increased odds of developing pouchitis (aOR 0.70, 95% CI 0.45–1.08). <b><i>Discussion/Conclusion:</i></b> Patients with ileitis, granulomas, or transmural inflammation at the time of colectomy were not at greater risk for development of pouchitis in the 2 years after IPAA. These pathological findings should not preclude IPAA for UC.

EP.TU.435A Rare Case of Granulomatous Appendicitis

Granulomatous appendicitis is a rare form of appendicitis due to a variety of causes such a foreign body, fungi, parasites, mycobacteria, Yesinia, Crohn's pathology and delayed appendicectomy. Definitive diagnosis necessitates histopathological analysis. We present an unusual case of granulomatous appendicitis in a young gentleman, incidentally detected at histopathology, along with a brief literature review. Patient presented with a classical clinical history and examination findings suggestive of acute appendicitis and underwent an emergency laparoscopic appendicectomy, followed by an uneventful post-operative recovery. Histopathological examination showed features of acute on chronic transmural inflammation with epithelioid granuloma, confirming diagnosis of granulomatous appendicitis. We hereby, aim to emphasize the significance of increased awareness required among general surgeons and pathologists, as patients with granulomatous appendicitis needs to be investigated further due to the likelihood of them having an underlying Crohn’s disease or developing it in future.

Single-cell analyses of Crohn’s disease tissues reveal intestinal intraepithelial T cells heterogeneity and altered subset distributions

Crohn’s disease (CD) is a chronic transmural inflammation of intestinal segments caused by dysregulated interaction between microbiome and gut immune system. Here, we profile, via multiple single-cell technologies, T cells purified from the intestinal epithelium and lamina propria (LP) from terminal ileum resections of adult severe CD cases. We find that intraepithelial lymphocytes (IEL) contain several unique T cell subsets, including NKp30+γδT cells expressing RORγt and producing IL-26 upon NKp30 engagement. Further analyses comparing tissues from non-inflamed and inflamed regions of patients with CD versus healthy controls show increased activated TH17 but decreased CD8+T, γδT, TFH and Treg cells in inflamed tissues. Similar analyses of LP find increased CD8+, as well as reduced CD4+T cells with an elevated TH17 over Treg/TFH ratio. Our analyses of CD tissues thus suggest a potential link, pending additional validations, between transmural inflammation, reduced IEL γδT cells and altered spatial distribution of IEL and LP T cell subsets.

An analysis of histopathological features of Crohn’s disease in surgical specimens

Background The diagnosis of Crohn’s disease is challenging. This study aimed to compare the histological features of Crohn’s disease and non-Crohn’s disease (i.e., other intestinal inflammatory diseases) in surgical specimens to identify histologic features for differential diagnosis. Methods We evaluated patients who were diagnosed with Crohn’s disease (n = 171) and non-Crohn’s disease (n = 215) between 2010 and 2015 and underwent surgical bowel resection. The frequency of histological features in surgical resection specimens were compared between these two patient groups. Results Transmural inflammation, subserosal lymphoid aggregates, fissures or sinus-like structures, granulomas or granuloma-like nodules, abnormalities of the enteric nervous system, and mucosa structure alterations (i.e., muscularis mucosae thickening or mucosal atrophy with pseudopyloric gland metaplasia) were more frequent in Crohn’s disease than non-Crohn’s disease (p < 0.001 for all). A set of 3 of the above pathological features had a specificity of 93.5% for Crohn’s disease. Some of the above histologic features were further grouped as chronic inflammatory change that includes granulomas or granuloma-like nodules, lymphoid aggregates in the muscularis propria or subserosa, fissures or sinus-like structures, and architectural abnormality (i.e., the presence of abnormal enteric nervous system and/or mucosa structure alterations). A combination of transmural inflammation, chronic inflammatory change, and architectural abnormality had a sensitivity of 92.4% and a specificity of 97.7% for Crohn’s disease. Conclusions A combination of transmural inflammation, chronic inflammatory change, and architectural abnormality in surgical bowel resection specimens is diagnostic for Crohn’s disease.

Pediatric Metastatic Crohn's Disease

Crohn's disease (CD) is a chronic, relapsing, idiopathic condition, characterized by granulomatous, transmural inflammation of the gastrointestinal tract, which can affect its entire length, from mouth to anus. Metastatic Crohn's disease (MCD) is a rare form of skin involvement and is defined by skin lesions without contiguity with the gastrointestinal tract. A 9-year-old patient presented with gastrointestinal complaints and gross skin lesions in the vulva and perianal region. The diagnosis of Crohn's disease was made when the patient was 11 years old, after being evaluated by the colorectal surgeon. Treatment was started with a “top-down” approach, with a sustained response for four years. Afterwards, there was a relapse of the skin disease in previously normal areas, without overt symptoms. Treatment consisted of steroids and local infiltration of infliximab, without improvement. A year later, there was a rapid progression of the skin lesions, and the drug changed to adalimumab, also without response and worsening of the skin lesions. The patient was admitted to the hospital and intravenous steroids were initiated, along with surgical debridement of the lesions. After some improvement, ustekinumab was initiated with satisfactory response. Pediatric MCD has an important impact on the patient's quality of life, with influences on growth and social development.

Histopathologic Manifestations of Crohn Disease in Duodenal Endoscopy Biopsy: The Value of Different Patterns of Involvement of Brunner Glands

Crohn disease (CD) not uncommonly involves the upper gastrointestinal tract, usually gastric antrum and proximal duodenum. The most consistent histopathologic manifestations of CD in duodenal biopsies are mucosal erosion, focal active inflammation, and granulomas. Since CD is a transmural inflammation and since duodenal biopsy may include submucosal Brunner glands, we aimed to find if CD has any specific histopathologic manifestations in Brunner gland lobules and their ducts compared to other duodenal inflammatory lesions. We carried out a retrospective review study over 6 years retrieving duodenal biopsy specimens in CD patients. We compared duodenal specimens involved by CD with other inflammatory lesions, for example, ulcerative colitis (UC), Helicobacter pylori-associated gastritis, non-Helicobacter gastritis, Celiac sprue, infections, and drugs. We found focal active duodenitis and erosion in CD cases and non-CD cases. Granulomas were found in CD cases. Five cases of CD showed inflammatory and degenerative changes of Brunner glands. Focal patchy active inflammation of only portion of submucosal Brunner gland lobule, mucosal Brunner glands, and their ducts was solely found in CD cases. This focally enhanced inflammation of Brunner glands was not found in other lesions. Whether this phenomenon of focal active “lobulitis” and “ductitis” is a specific sign of duodenal CD compared to UC and other inflammatory lesions warrants verification. We encourage endoscopists to include submucosal Brunner lobules in their duodenal biopsy samples and pathologists to look for these patterns of involvement particularly in patients suspected of CD.

Relevance of monitoring transmural disease activity in patients with Crohn’s disease: current status and future perspectives

Treatment targets of inflammatory bowel diseases (IBD), ulcerative colitis (UC) and Crohn’s disease (CD) have evolved over the last decade. Goals of therapy consisting of symptom control and steroid sparing have shifted to control of disease activity with endoscopic remission being an important endpoint. Unfortunately, this requires ileocolonoscopy, an invasive procedure. Biomarkers [C-reactive protein (CRP) and fecal calprotectin (FCP)] have emerged as surrogates for endoscopic remission and disease activity, but also have limitations. Despite this evolution, we must not lose sight that CD involves transmural inflammation, not fully appreciated with ileocolonoscopy. Therefore, transmural assessment of disease activity by cross-sectional imaging, in particular with magnetic resonance enterography (MRE) and intestinal ultrasonography (IUS), is vital to fully understand disease control. Bowel-wall thickness (BWT) is the cornerstone in assessment of transmural inflammation and BWT normalization, with or without bloodflow normalization, the key element demonstrating resolution of transmural inflammation, namely transmural healing (TH) or transmural remission (TR). In small studies, achievement of TR has been associated with improved long-term clinical outcomes, including reduced hospitalization, surgery, escalation of treatment, and a decrease in clinical relapse over endoscopic remission alone. This review will focus on the existing literature investigating the concept of TR or residual transmural disease and its relation to other existing treatment targets. Current data suggest that TR may be the next logical step in the evolution of treatment targets.

Ultrasonographic Halo Score in giant cell arteritis: association with intimal hyperplasia and ischaemic sight loss

Objectives We investigated the relationship between the ultrasonographic Halo Score and temporal artery biopsy (TAB) findings in GCA. Methods This is a prospective study including 90 patients suspected of having GCA. Ultrasonography of temporal/axillary arteries and a TAB were obtained in all patients at baseline. An experienced pathologist evaluated whether TAB findings were consistent with GCA, and whether transmural inflammation, giant cells and intimal hyperplasia were present. Ultrasonographic Halo Scores were determined. Receiver operating characteristic analysis was performed. Results Twenty-seven patients had a positive TAB, while 32 patients with a negative TAB received a clinical diagnosis of GCA after 6 months of follow-up. Patients with a positive TAB showed higher Halo Scores than patients with a negative TAB. The presence of intimal hyperplasia in the biopsy, rather than the presence of transmural inflammation or giant cells, was associated with elevated Halo Scores in patients with GCA. The Halo Score discriminated well between TAB-positive patients with and without intimal hyperplasia, as indicated by an area under the curve of 0.82 in the receiver operating characteristic analysis. Patients with a positive TAB and intimal hyperplasia more frequently presented with ocular ischaemia (40%) than the other patients with GCA (13–14%). Conclusion The ultrasonographic Halo Score may help to identify a subset of GCA patients with intimal hyperplasia, a TAB feature associated with ischaemic sight loss.