Clinical characteristics and imaging features of small bowel adenocarcinomas in Crohn's disease

Small Bowel Carcinoma in the Setting of Inflammatory Bowel Disease

Small bowel carcinomas are rare in the general population, but the incidence is increasing. Patients with inflammatory bowel diseases (IBDs) are at significantly higher risk of small bowel adenocarcinomas than their non-IBD counterparts, with Crohn's patients having at least a 12-fold increased risk and ulcerative colitis patients with a more controversial and modest 2-fold increased risk compared with the general population. IBD patients with small bowel carcinomas present with nonspecific symptoms that overlap with typical IBD symptoms, and this results in difficulty making a preoperative diagnosis. Cross-sectional imaging is rarely diagnostic, and most cancers are found incidentally at the time of surgery performed for an IBD indication. As such, most small bowel carcinomas are found at advanced stages and carry a poor prognosis. Oncologic surgical resection is the treatment of choice for patients with locoregional disease with little evidence available to guide adjuvant therapy. Patients with metastatic disease are treated with systemic chemotherapy, and surgery is reserved for palliation in this population. Prognosis is poor with few long-term survivors reported.

Focal loss of mural stratification as a radiological predictor for small bowel adenocarcinoma in Crohn's disease

AIM

Patients with Crohn's disease (CD) are at higher risk of small bowel adenocarcinoma (SBA). We aimed to identify radiological predictors of SBA in CD.

METHODS

We conducted a retrospective case-control study at two tertiary inflammatory bowel disease centers and identified CD patients diagnosed with SBA between 2003 and 2019. Patients were matched with up to four controls. Pre-operative imaging (magnetic resonance imaging (MRI) or computed tomography (CT)) were reviewed by three gastrointestinal radiologists.

RESULTS

Nineteen patients with CD-associated SBA with a mean age of 54.9 and 32 matched controls were included. Mean length of small bowel involvement was 216 (± 188) mm in the SBA group versus 156 (± 167) mm in the control group (p = 0.76). Only 11.8 % of cases had a diagnosis of SBA made preoperatively. In univariate analysis, focal loss of mural stratification (odds ratio [OR], 11; 95%CI, 2.43-49.5, p = 0.002), and wall thickening (OR, 1.32; 95%CI, 1.05-1.66, p = 0.02) were significantly associated with SBA. After adjustment, focal loss of mural stratification was the only independent risk factor (OR, 11; 95 % CI, 2.43-49.5, p = 0.002).

CONCLUSIONS

Focal loss of mural stratification was identified as a predictor of CD-associated SBA, which should be described in imaging reports and further validated.

Intestinal MRI in Inflammatory Bowel Disease - Literature and Survey-Based Recommendations regarding Reporting by the German Radiological Society (DRG) and the German Competence Network for Inflammatory Bowel Diseases

BACKGROUND

MR-enterography/enteroclysis (MRE) is increasingly used for primary diagnosis, detection of complications, and monitoring of patients with inflammatory bowel disease (IBD). Standardization of reporting is relevant to ensure quality of the methodology and to improve communication between different faculties. The current manuscript describes the features that are required for optimized reporting of MRE in IBD.

METHODS

An expert consensus panel of radiologists and gastroenterologists conducted a systematic search of the literature. In a Delphi process, members of the German Radiological Society (DRG) and members of the Competence Network for Inflammatory Bowel Diseases voted on relevant criteria for the reporting of findings in MRE. Based on the voting results, statements were developed by the expert consensus panel.

RESULTS

Clinically relevant aspects of MRE findings have been defined to optimize reporting and to standardize terminology. Minimal requirements for standardized reporting are suggested. The statements focus on the description of disease activity as well as on complications of IBD. Attributes of intestinal inflammation are described and illustrated by exemplary images.

CONCLUSION

The current manuscript provides standardized parameters and gives practical recommendations on how to report and how to characterize MRE findings in patients with IBD.

KEY POINTS

· Systematic overview provides practice-oriented recommendations and names and evaluates the decisive criteria for reporting and interpretation of MRI in inflammatory bowel disease.. · Standardized terminology and reporting criteria for MRI in IBD improves interdisciplinary communication.. · Standardized collection and documentation of MRI findings in IBD helps to further establish the method and to improve care for IBD patients..

CITATION FORMAT

· Wessling J, Kucharzik T, Bettenworth D et al. Intestinal MRI in Inflammatory Bowel Disease - Literature and Survey-Based Recommendations regarding Reporting by the German Radiological Society (DRG) and the German Competence Network for Inflammatory Bowel Diseases. Fortschr Röntgenstr 2023; 195: 675 - 690.

Inflammatory Bowel Disease Treatment in Cancer Patients-A Comprehensive Review

Inflammatory bowel disease (IBD) is a chronic disease for which medical treatment with immunomodulating drugs is increasingly used earlier to prevent disability. Additionally, cancer occurrence in IBD patients is increased for several reasons, either IBD-related or therapy-associated. Doctors are therefore facing the challenge of managing patients with IBD and a past or current malignancy and the need to balance the risk of cancer recurrence associated with immunosuppressive drugs with the potential worsening of IBD activity if they are withdrawn. This review aims to explore the features of different subtypes of cancer occurring in IBD patients to present current evidence on malignancy recurrence risk associated with IBD medical therapy along with the effects of cancer treatment in IBD and finally to discuss current recommendations on the management of these patients. Due to sparse data, a case-by-case multidisciplinary discussion is advised, including inputs from the gastroenterologist, oncologist, and patient.

Preoperative Predictors of Neoplasia in Patients Undergoing Small Bowel Resection for Complicated Crohn’s Disease: A Multicentre Case-Control Study

Crohn’s disease (CD) is associated with an increased risk of small bowel neoplasia (SBN). We aimed to assess preoperative predictors of SBN in CD patients. We conducted a retrospective case-control study including CD patients who underwent surgery: cases were diagnosed with SBN on histopathological analysis and controls had no neoplasia. Preoperative cross-sectional imaging was reviewed by a panel of blinded expert radiologists. Fifty cases were matched to one hundred and fifty consecutive controls. In multivariable analysis, predictors of SBN were age ≥ 50 years (OR = 28, 95% CI = 5.05–206), median CD duration ≥ 17.5 years (OR = 4.25, 95% CI = 1.33–14.3), and surgery for stricture (OR = 5.84, 95% CI = 1.27–35.4). The predictors of small bowel adenocarcinoma were age ≥ 50 years (OR = 5.14, 95% CI = 2.12–12.7), CD duration ≥ 15 years (OR = 5.65, 95% CI = 2.33–14.3), and digestive wall thickening > 8 mm (OR = 3.79, 95% CI = 1.45–11.3). A predictive score based on the aforementioned factors was constructed. Almost 73.7% of patients with a high score had SBA. Old age, long small bowel CD duration, and stricture predicted the presence of SBN, particularly adenocarcinoma when patients have digestive wall thickening > 8 mm on preoperative imaging.

[Position paper on reporting of intestinal ultrasound findings in patients with inflammatory bowel disease]

BACKGROUND

Intestinal ultrasound is increasingly used for primary diagnosis, detection of complications and monitoring of patients with Crohn's disease and ulcerative colitis. Standardization of reporting is relevant to ensure quality of the methodology and to improve communication between different specialties. The current manuscript describes the features required for optimized reporting of intestinal ultrasound findings in inflammatory bowel disease (IBD).

METHODS

An expert consensus panel of gastroenterologists, radiologists, pathologists, paediatric gastroenterologists and surgeons conducted a systematic literature search. In a Delphi- process members of the Kompetenznetz Darmerkrankungen in collaboration with members of the German Society for Radiology (DRG) voted on relevant criteria for reporting of findings in intestinal ultrasound. Based on the voting results statements were agreed by expert consensus.

RESULTS

Clinically relevant aspects of intestinal ultrasound (IUS) findings have been defined to optimize reporting and to standardize terminology. Minimal requirements for standardized reporting are suggested. The statements focus on description of disease activity as well as on complications of IBD. Attributes of intestinal inflammation are described and illustrated by exemplary images.

CONCLUSION

The current manuscript provides practical recommendations on how to standardize documentation and reporting from intestinal ultrasound findings in patients with IBD.

The Role of Magnetic Resonance Enterography in Crohn’s Disease: A Review of Recent Literature

Inflammatory bowel disease (IBD) is the term used to identify a form of chronic inflammation of the gastrointestinal tract that primarily contemplates two major entities: ulcerative colitis (UC) and Crohn’s disease (CD). The classic signs are abdominal pain and diarrhoea that correlate with the localization of gastro-enteric disease, although in this pathology extraintestinal symptoms may coexist. The diagnosis of CD relies on a synergistic combination of clinical, laboratory (stool and biochemical), cross-sectional imaging evaluation, as well as endoscopic and histologic assessments. The purpose of this paper is to prove the role of imaging in the diagnosis and follow-up of patients with CD with particular focus on recent innovations of magnetic resonance enterography (MRE) as a pivotal diagnostic tool, analysing the MRE study protocol and imaging features during the various phases of disease activity and its complications.

ECCO-ESGAR Topical Review on Optimizing Reporting for Cross-Sectional Imaging in Inflammatory Bowel Disease

BACKGROUND AND AIMS

The diagnosis and follow up of patients with inflammatory bowel disease [IBD] requires cross-sectional imaging modalities, such as intestinal ultrasound [IUS], magnetic resonance imaging [MRI] and computed tomography [CT]. The quality and homogeneity of medical reporting are crucial to ensure effective communication between specialists and to improve patient care. The current topical review addresses optimized reporting requirements for cross-sectional imaging in IBD.

METHODS

An expert consensus panel consisting of gastroenterologists, radiologists and surgeons convened by the ECCO in collaboration with ESGAR performed a systematic literature review covering the reporting aspects of MRI, CT, IUS, endoanal ultrasonography and transperineal ultrasonography in IBD. Practice position statements were developed utilizing a Delphi methodology incorporating two consecutive rounds. Current practice positions were set when ≥80% of the participants agreed on a recommendation.

RESULTS

Twenty-five practice positions were developed, establishing standard terminology for optimal reporting in cross-sectional imaging. Assessment of inflammation, complications and imaging of perianal CD are outlined. The minimum requirements of a standardized report, including a list of essential reporting items, have been defined.

CONCLUSIONS

This topical review offers practice recommendations to optimize and homogenize reporting in cross-sectional imaging in IBD.

Malignant Small Bowel Neoplasms:a review of post-contrast multiphasic multidetector computed tomography

Small bowel neoplasms are rare and account for 3-6% of all gastrointestinal neoplasms. For the diagnosis of small bowel neoplasms, differentiating normal bowel tissue from tumor is critical and depends on imaging modality and scanning techniques. The detection and characterization of small bowel neoplasms have recently improved with the advance of computed tomography (CT) technology. Post-contrast multiphasic CT is an aid to detection and recognition of the vascular nature of small bowel neoplasms. Understanding the typical post-contrast multiphasic CT features of small bowel neoplasms is important because of overlapping features and the necessity of evaluating associated complications and metastases to lymph node and other organs. However, accurate classification of pathologies is still challenging in clinical practice. Texture analysis can quantify complex mathematical patterns within the gray-level distribution of the pixels and voxels of digital images, and texture analysis of the post-contrast multidetector CT data of various tumors has been attracting attention in recent years. The aim of this article is to provide a comprehensive guide to the relevant imaging features for different types of malignant small bowel neoplasms. J. Med. Invest. 69 : 19-24, February, 2022.

Small bowel adenocarcinoma in Crohn's disease: a systematic review and meta-analysis of the prevalence, manifestation, histopathology, and outcomes

BACKGROUND AND AIMS

Small bowel adenocarcinoma (SBA) is a rare neoplasm that is associated with Crohn's disease (CD). This study aims to quantify the prevalence of CD-SBA, review the current evidence of histopathology and molecular analysis findings, and identify the clinical presentation and outcomes of CD-SBA.

METHODS

Electronic databases Medline and Embase were searched for articles describing SBA in inflammatory bowel disease patients. The histopathology, molecular analysis findings, clinical presentation, prevalence, and outcomes of CD-SBA were extracted, and results were pooled with random effects.

RESULTS

In total, 33 articles were included in the analysis. Prevalence of SBA was 1.15 (CI: 0.31-2.33) per 1000 CD patients. Only 11% (CI: 0.04-0.21) of CD-SBA patients had observable radiological features. CD-SBA was most commonly found in the ileum (84%), diagnosed at stage 2 (36%), with main presenting complaints including obstruction, weight loss, and abdominal pain. Significant histopathological findings included adjacent epithelial dysplasia, and an equal distribution of well-differentiated (49%) and poorly differentiated subtypes (46%). Most prevalent genetic mutation was KRAS mutation (18%), followed by mismatch repair deficiency (9.7%). The 5-year overall survival for CD-SBA patients was 29% (CI: 0.18-0.41), and 33% (CI: 0.26-0.41) for de novo SBA. No statistically significant increase in risk for CD-SBA was noted for treatment with thiopurines, steroids, and 5-ASA.

CONCLUSION

Our meta-analysis found the prevalence of CD-SBA to be 1.15 per 1000 CD patients. The 5-year overall survival for CD-SBA was poor. The presenting symptoms were non-specific, and therefore the diagnosis requires a high index of suspicion.

The Risk of Malignancies in Celiac Disease-A Literature Review

Celiac disease (CeD) is an immune-mediated enteropathy precipitated by ingestion of gluten in genetically predisposed individuals. Considering that CeD affects approximately 1% of the Western population, it may be considered a global health problem. In the large majority of cases, CeD has a benign course, characterized by the complete resolution of symptoms and a normal life expectancy after the beginning of a gluten-free-diet (GFD); however, an increased risk of developing malignancies, such as lymphomas and small bowel carcinoma (SBC), has been reported. In particular, enteropathy-associated T-cell lymphoma (EATL), a peculiar type of T-cell lymphoma, is characteristically associated with CeD. Moreover, the possible association between CeD and several other malignancies has been also investigated in a considerable number of studies. In this paper, we aim to provide a comprehensive review of the current knowledge about the associations between CeD and cancer, focusing in particular on EATL and SBC, two rare but aggressive malignancies.

Medical and Endoscopic Management of Crohn Disease

ABSTRACT

In this review, through a series of questions and answers, we explore the current approach to classifying patients with Crohn disease into low-risk (mild-moderate) and high-risk (moderate-severe) categories with the recommended treatment approaches per guidelines from the International Organization for the Study of Inflammatory Bowel Diseases, American Gastroenterological Association, the American College of Gastroenterology, and the European Crohn's and Colitis Organization detailed here. The development pipeline of potential therapies is also summarized. We also review key information from magnetic resonance enterography and pelvis imaging studies that the abdominal radiologist can communicate to a multidisciplinary treatment team that includes gastroenterologists and colorectal surgeons, with a goal of achieving optimal patient outcomes. Lastly, endoscopic and radiological treatment targets in a treat-to-target approach in Crohn disease are explored.

The risk of small bowel adenocarcinoma in patients with Crohn's disease

Introduction

Small bowel adenocarcinoma (SBA) is an unusual complication of Crohn’s disease (CD).

Aim

To describe the incidence rate, clinical features, and outcomes of SBA in a group of subsequent patients with CD.

Material and methods

We retrospectively analysed outpatient and hospital records and identified a group of patients with diagnosed CD. Then we reviewed all medical records of patients who reported for follow-up visits in a 14-year period. We identified a group of 103 patients, whose medical records were evaluated for the presence of SBA.

Results

Long-term follow-up carried out in the group of consecutively treated patients with CD revealed an 0.97% incidence rate of SBA. Cancer was located in the ileum and the clinical presentation was subileus and anaemia. The patient underwent ileocaecal resection, and the postoperative period was uneventful.

Conclusions

SBA is a rare complication of CD. Although the authors are aware that the number of patients enrolled in the study is insufficient to draw far-reaching conclusions, the results obtained are significant for determination of the incidence rate of SBA in the Caucasian population of patients with CD. The key issue of effective treatment of patients with SBA was early detection of the lesion and R0 resection with proper lymphadenectomy. However, it is worth noting that in more advanced stages of SBA the future belongs to, and outcome improvement depends on, new regimes of adjuvant personalised chemotherapies. Further studies on the mechanisms of carcinogenesis in patients with CD are essential.

Small bowel adenocarcinoma in Crohn's disease: a rare but devastating complication

BACKGROUND

Small bowel adenocarcinoma (SBA) remains a rare entity but occurs at increased frequency in the setting of chronic Crohn's disease (CD). Our aim was to study the presentation, diagnosis and prognosis of SBA in patients undergoing surgery for CD at a single institution.

METHODS

We reviewed the medical records of all patients with CD complicated by adenocarcinoma of the small bowel from 2000 to 2017. Descriptive statistics and Kaplan-Meier overall survival estimates were calculated.

RESULTS

In total, 22 patients (14 males) with CD (median duration of Crohn's diagnosis 32 years) were diagnosed with SBA and underwent surgical resection (8 isolated small bowel resections, 12 ileocolic resections, and 2 total proctocolectomies). The median patient age at the time of diagnosis was 54 years (range 22-82 years). A total of 17 patients (77%) underwent cross-sectional CT imaging within 3 months of surgery, a cancer diagnosis was suggested in only one patient. In one other patient, SBA was diagnosed preoperatively on endoscopic biopsy of the terminal ileum. The remaining patients were operated on for obstruction (n = 17), abscess or fistulizing disease (n = 2), and sigmoid cancer (n = 1). For these 20 (90%) patients not suspected to have SBA on preoperative assessment, 5 (25%) were diagnosed intraoperatively on frozen section and 15 (75%) were unexpectedly diagnosed postoperatively on final pathology. T staging was characterized by more advanced tumors (T4: 59%, T3: 27%, T2: 9%, and T1: 5%). Nine patients (41%) had nodal involvement and five patients (23%) had hepatic and/or peritoneal carcinomatosis. The 1-, 3-, and 5-year survival estimates for our cohort were 84%, 30%, and 10%, respectively. Median survival was 30.5 months with median follow-up of 23 months (range 6-84 months).

CONCLUSIONS

SBA in the setting of CD is most commonly found incidentally after surgical resection for benign indications. As such, any suspicious finding at the time of surgery in a patient with chronic CD should warrant careful investigation with frozen section and/or resection. Prognosis for CD complicated by SBA remains poor even in the modern era.

Small Bowel Adenocarcinoma: Is There a Difference in Survival for Crohn's Versus Sporadic Cases?

BACKGROUND AND AIMS

It is well known that Crohn's disease is a risk factor for the development of small bowel adenocarcinoma. However, the association between Crohn's disease-associated small bowel adenocarcinoma and survival is less understood. The goal of this study was to determine the impact of Crohn's disease on survival in small bowel adenocarcinoma.

METHODS

Patients with small bowel adenocarcinoma, either associated with Crohn's disease or diagnosed sporadic, were identified in the National Cancer Database from 2004-2016. The primary outcome was overall survival.

RESULTS

Of 2668 patients, 493 had Crohn's disease-associated small bowel adenocarcinoma and 2175 had sporadic small bowel adenocarcinoma. Crohn's disease patients were more likely to present at a younger age [62 vs 65, p < 0.001], have tumours located in the ileum [62.7% vs 25.0%, p < 0.001], and have poorly differentiated tumours [47.0% vs 31.7%, p < 0.001] compared with sporadic small bowel adenocarcinoma. Factors associated with significantly decreased survival included older age (hazard ratio [HR]: 1.02, 95% confidence interval [CI]: 1.02-1.03, p < 0.00)], higher Charlson score [HR: 1.39, 95% CI: 1.13-1.72, p = 0.002], higher tumour grade [HR: 1.09, 95% CI: 1.04-1.14, p < 0.001], positive surgical margins [HR: 1.60, 95% CI: 1.39-1.84, p < 0.001], and higher stage of disease [HR: 1.90, 3.75, 8.13, 95% CI: 1.37-2.64, 2.68-5.24, 5.77-11.47, for II, III, IV, respectively, compared with I, all p < 0.001]. Receipt of chemotherapy was associated with significantly improved survival [HR: 0.61, 95% CI: 0.53-0.70, p < 0.001]. Crohn's disease [HR: 1.01, 95% CI: 0.99-1.02, p = 0.39], was not significantly associated with survival.

CONCLUSION

Compared with sporadic patients, Crohn's disease patients have similar overall survival, and Crohn's disease is not an independent risk factor for mortality.

Small Bowel Carcinomas Associated with Immune-Mediated Intestinal Disorders: The Current Knowledge

Small bowel carcinomas (SBC) are uncommon neoplasms, whose predisposing conditions include hereditary syndromes and immune-mediated intestinal disorders including coeliac disease (CD) and Crohn's disease (CrD). Although both CD-associated SBC (CD-SBC) and CrD-associated SBC (CrD-SBC) arise from an inflammatory background, they differ substantially in tumour cell phenotype, frequency of microsatellite instability and nuclear β-catenin expression, as well as in prognosis. For these patients, high tumour-infiltrating lymphocyte density and glandular/medullary histotype represent independent positive prognostic factors. Dysplasia adjacent to SBC is rare and characterized by intestinal phenotype and nuclear β-catenin in CD, while it is frequent and typified by gastro-pancreatobiliary marker expression and preserved membranous β-catenin in CrD. Recent evidence suggests that Epstein-Barr virus-positive dysplasia and SBC, albeit exceptional, do exist and are associated with CrD. In this review, we summarize the novel pathological and molecular insights of clinical and therapeutic interest to guide the care of CD-SBC and CrD-SBC.

Computed Tomography Enterography

Computed tomography (CT) enterography is a noninvasive imaging modality with superb spatial and temporal resolution, specifically tailored to evaluate the small bowel. It has several advantages over other radiologic and optical imaging modalities, all of which serve as complementary investigations to one another. This article describes CTE technique, including dose reduction techniques, special considerations for the pediatric population, common technical and interpretive pitfalls, and reviews some of the more common small bowel entities seen with CTE.

Consensus Recommendations for Evaluation, Interpretation, and Utilization of Computed Tomography and Magnetic Resonance Enterography in Patients With Small Bowel Crohn's Disease

Computed tomography and magnetic resonance enterography have become routine small bowel imaging tests to evaluate patients with established or suspected Crohn's disease, but the interpretation and use of these imaging modalities can vary widely. A shared understanding of imaging findings, nomenclature, and utilization will improve the utility of these imaging techniques to guide treatment options, as well as assess for treatment response and complications. Representatives from the Society of Abdominal Radiology Crohn's Disease-Focused Panel, the Society of Pediatric Radiology, the American Gastroenterological Association, and other experts, systematically evaluated evidence for imaging findings associated with small bowel Crohn's disease enteric inflammation and established recommendations for the evaluation, interpretation, and use of computed tomography and magnetic resonance enterography in small bowel Crohn's disease. This work makes recommendations for imaging findings that indicate small bowel Crohn's disease, how inflammatory small bowel Crohn's disease and its complications should be described, elucidates potential extra-enteric findings that may be seen at imaging, and recommends that cross-sectional enterography should be performed at diagnosis of Crohn's disease and considered for small bowel Crohn's disease monitoring paradigms. A useful morphologic construct describing how imaging findings evolve with disease progression and response is described, and standard impressions for radiologic reports that convey meaningful information to gastroenterologists and surgeons are presented.

Consensus Recommendations for Evaluation, Interpretation, and Utilization of Computed Tomography and Magnetic Resonance Enterography in Patients With Small Bowel Crohn's Disease

Computed tomography and magnetic resonance enterography have become routine small bowel imaging tests to evaluate patients with established or suspected Crohn's disease, but the interpretation and use of these imaging modalities can vary widely. A shared understanding of imaging findings, nomenclature, and utilization will improve the utility of these imaging techniques to guide treatment options, as well as assess for treatment response and complications. Representatives from the Society of Abdominal Radiology Crohn's Disease-Focused Panel, the Society of Pediatric Radiology, the American Gastroenterological Association, and other experts, systematically evaluated evidence for imaging findings associated with small bowel Crohn's disease enteric inflammation and established recommendations for the evaluation, interpretation, and use of computed tomography and magnetic resonance enterography in small bowel Crohn's disease. This work makes recommendations for imaging findings that indicate small bowel Crohn's disease, how inflammatory small bowel Crohn's disease and its complications should be described, elucidates potential extra-enteric findings that may be seen at imaging, and recommends that cross-sectional enterography should be performed at diagnosis of Crohn's disease and considered for small bowel Crohn's disease monitoring paradigms. A useful morphologic construct describing how imaging findings evolve with disease progression and response is described, and standard impressions for radiologic reports that convey meaningful information to gastroenterologists and surgeons are presented. ^©2018, RSNA, AGA Institute, and Society of Abdominal Radiology This article is being published jointly in Radiology and Gastroenterology.

Enterocutaneous fistulas: a primer for radiologists with emphasis on CT and MRI

Abstract

Enterocutaneous fistulas (ECFs) represent abnormal communications between the gastrointestinal tract and the skin. Nowadays, the majority (~80%) of ECFs develops secondary to abdominal surgeries; alternative, less common causes include chronic inflammatory bowel diseases (IBD) such as Crohn’s disease, tumours, and radiation enteritis in descending order of frequency. These rare disorders require thorough patient assessment and multidisciplinary management to limit the associated morbidity and mortality. This pictorial review includes an overview of causes, clinical manifestations, complications and management of ECFs. Afterwards, the imaging appearances, differential diagnoses, and therapeutic options of post-surgical, IBD-related, and malignant ECFs are presented with case examples. Most of the emphasis is placed on the current pivotal role of CT and MRI, which comprehensively depict ECFs providing cross-sectional information on the underlying postsurgical, neoplastic, infectious, or inflammatory conditions. Radiographic fistulography remains a valid technique, which rapidly depicts the ECF anatomy and confirms communication with the bowel. The aim of this paper is to increase radiologists’ familiarity with ECF imaging, thus allowing an appropriate choice between medical, interventional, or surgical treatment, ultimately resulting in higher likelihood of therapeutic success.

Teaching Points

• Enterocutaneous fistulas may complicate abdominal surgery, sometimes Crohn’s disease and tumours.

• The high associated morbidity and mortality result from sepsis, malnutrition and metabolic imbalance.

• The multidisciplinary management of ECFs requires thorough imaging for correct therapeutic choice.

• Radiographic fistulography rapidly depicts fistulas and communicating bowel loops in real-time.

• Multidetector CT and MRI provide cross-sectional information on fistulas and underlying diseases.

Multidetector CT enterography of focal small bowel lesions: a radiological-pathological correlation

Focal small bowel lesions present a diagnostic challenge for both the radiologist and gastroenterologist. Both the detection and characterization of small bowel masses have greatly improved with the advent of multidetector CT enterography (MD-CTE). As such, MD-CTE is increasingly utilized in the workup of occult gastrointestinal bleeding. In this article, we review the spectrum of focal small bowel masses with pathologic correlation. Adenocarcinoma, the most common primary small bowel malignancy, presents as a focal irregular mass occasionally with circumferential extension leading to obstruction. Small bowel carcinoid tumors most commonly arise in the ileum and are characterized by avid enhancement and marked desmoplastic response of metastatic lesions. Aneurysmal dilatation of small bowel is pathognomonic for lymphoma and secondary findings of lymphadenopathy and splenomegaly should be sought. Benign small bowel masses such as leiomyoma and adenoma may be responsible for occult gastrointestinal bleeding. However, primary vascular lesions of the small bowel remain the most common cause for occult small bowel gastrointestinal bleeding. The arterial phase of contrast obtained with CTE aids in recognition of the vascular nature of these lesions. Systemic conditions such as Peutz-Jeghers syndrome and Crohn's disease may be suggested by the presence of multiple small bowel lesions. Lastly, potential pitfalls such as ingested material should be considered when faced with focal small bowel masses.

Small bowel adenocarcinoma complicating Crohn's disease: a single-centre experience emphasizing the importance of screening for dysplasia

Small bowel adenocarcinoma (SBA) complicating Crohn's disease (CD) is rare and generally found incidentally on surgical specimens. We report our experience in CD-associated SBA observed this last decade in a tertiary referral centre in order to update its incidence, clinical presentation and pathological features. All SBAs diagnosed in patients who underwent surgery for CD between 2006 and 2016 were retrospectively included. Clinico-pathological characteristics were reviewed, and follow-up was updated. SBA was diagnosed in 9 (1.7%) of 522 patients who underwent SB resection(s) after a median CD duration of 15 years [0-32]. The median age at diagnosis was 46 years. Seven (78%) patients had obstructive symptoms refractory to medical treatment. Pre-operative biopsy revealed neoplasia in five (56%) patients (dysplasia in three and SBA in two) justifying the surgery. Two (29%) of the seven patients with imaging had features suggestive of cancer. In all specimens, SBA developed in active ileitis with adjacent dysplasia. Stage I low-grade tubulo-glandular adenocarcinoma was observed in 33% of patients. Stage IV high-grade adenocarcinoma was observed in 56% of patients, and mucinous/signet ring cell differentiation predominated in 44% of patients. Molecular analysis showed no BRAF mutation, a KRAS mutation in one case and a microsatellite instability phenotype suggestive of Lynch syndrome in one case. After a median follow-up of 24 months [7-82], four (44%) patients died with advanced stage IV SBA. This surgical series confirms that CD-associated SBA is rare with an incidence of 1.7%. Adjacent dysplasia was present in all specimens and was identified before surgery in all patients who benefit from ileal biopsies. This strengthens the importance of screening all longstanding CD by endoscopy if surgery is not considered.

Crohn's disease diagnosis, treatment approach, and management paradigm: what the radiologist needs to know

Crohn's disease is one of the major subtypes of idiopathic inflammatory bowel disease and is characterized by chronic transmural intestinal inflammation of the gastrointestinal tract anywhere from mouth to the anus, with a predilection for the small bowel. Cross-sectional imaging with computed tomography and magnetic resonance enterography plays a key role in confirming diagnosis, identifying and managing complications, assessing disease severity, and identifying response to medical therapy. This review will focus on the role of radiologists in the diagnosis and assessment of Crohn's disease. Additionally, a review of current medical therapy approaches, available medications, and side effects will be discussed. The review will also highlight key complications of medical therapy and associated diseases that should be evaluated by the radiologist with cross-sectional imaging.

Endoscopic Detection of Small Bowel Dysplasia and Adenocarcinoma in Crohn's Disease: A Prospective Cohort-Study in High-Risk Patients

BACKGROUND AND AIMS

Crohn's disease [CD] is associated with an increased risk of small bowel adenocarcinoma [SBA]. There are no recommendations on endoscopic screening of SBA in CD patients. The aim of this study was to evaluate the feasibility and value of endoscopic screening for SBA in CD patients at high-risk of SBA.

METHODS

We performed an exploratory multi-centre study in a prospective cohort of CD patients at high-risk of SBA defined as long-term small bowel disease without bowel resection for the past 10 years. Depending on the location of the disease, baseline upper and/or lower enteroscopies were performed. Random and targeted biopsies using chromoendoscopy were taken. Patients were followed-up for at least 1 year after inclusion.

RESULTS

In total, 101 patients [62 men; median age: 48 years; median duration of disease: 19 years] were recruited in ten centres. The endoscopic procedure was incomplete in 47 cases because of impassable strictures and dilation was performed in four patients. Indeterminate small bowel dysplasia was identified in two patients at endoscopic screening; SBA was confirmed in one after surgical resection. With an at least 1-year follow-up duration, two additional cases of SBA were identified in patients who underwent surgery for obstruction, resulting in a 33% sensitivity rate for SBA endoscopic screening.

CONCLUSION

In a cohort of high-risk patients, the prevalence of dysplasia and SBA on CD was 4%. Because of its low sensitivity, endoscopic screening cannot be recommended for surveillance in CD patients at high-risk of SBA.