Identification of the distinguishing features of Crohn's disease and ischemic colitis using computed tomographic enterography

Gut inflammation induced by drugs: Can pathology help to differentiate from inflammatory bowel disease?

Drug‐induced mucosal injury (DIMI) in the gastrointestinal tract is important to recognise, partly because cessation of the culprit agent alone may result in resolution of symptoms. An ever‐growing list of medications, including newer immunotherapeutic agents and targeted therapies, can cause gastrointestinal inflammation of varying severity. However, the diagnosis of DIMI is challenging, as a single drug can induce a variety of histopathological patterns of injury including acute colitis, chronic colitis, microscopic colitis, apoptotic colopathy, and ischaemic‐type colitis. An additional consideration is the potential clinical, endoscopic and histological overlap of DIMI with gastrointestinal mucosal injury secondary to other entities such as inflammatory bowel disease (IBD). We discuss DIMI of the gastrointestinal tract with an emphasis on histological patterns that mimic IBD, histological features which may distinguish the two entities, and the diagnostic role and limitations of the pathologist.

Ischaemic colitis: practical challenges and evidence-based recommendations for management

Ischaemic colitis (IC) is a common condition with rising incidence, and in severe cases a high mortality rate. Its presentation, severity and disease behaviour can vary widely, and there exists significant heterogeneity in treatment strategies and resultant outcomes. In this article we explore practical challenges in the management of IC, and where available make evidence-based recommendations for its management based on a comprehensive review of available literature. An optimal approach to initial management requires early recognition of the diagnosis followed by prompt and appropriate investigation. Ideally, this should involve the input of both gastroenterology and surgery. CT with intravenous contrast is the imaging modality of choice. It can support clinical diagnosis, define the severity and distribution of ischaemia, and has prognostic value. In all but fulminant cases, this should be followed (within 48 hours) by lower gastrointestinal endoscopy to reach the distal-most extent of the disease, providing endoscopic (and histological) confirmation. The mainstay of medical management is conservative/supportive treatment, with bowel rest, fluid resuscitation and antibiotics. Specific laboratory, radiological and endoscopic features are recognised to correlate with more severe disease, higher rates of surgical intervention and ultimately worse outcomes. These factors should be carefully considered when deciding on the need for and timing of surgical intervention.

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.

Ischemic colitis caused by polycythemia vera: A case report and literature review

Polycythemia vera (PV) is a chronic myeloproliferative disorder originating from hematopoietic stem cells and complicated by thrombosis and bleeding. This report describes a case of ischemic colitis (IC) caused by PV and includes a review of the relevant literature. The patient was a 59-year-old male with a history of PV who presented with abdominal pain and hematochezia. Colonoscopy and histopathological examination results indicated suspected ischemic bowel disease. Following experimental anticoagulant therapy for 7 days, the patient no longer experienced abdominal pain and hematochezia had resolved. Colonoscopy review showed no obvious anomalies 1 month later. These data demonstrated that PV is an uncommon cause of IC.