P2544 - Terminal Ileitis: It’s Not Always Inflammatory Bowel Disease

Natalie E. Mitchell, MD¹, Jerome Edelson, MD¹, Nicole M. Harrison, MD^2
1Brooke Army Medical Center, Fort Sam Houston, TX; ²San Antonio Uniformed Services Health Education Consortium, Fort Sam Houston, TX

Introduction: Terminal ileitis is most classically associated with Crohn’s disease (CD). Here, we present a case of a young, Active Duty solider with acute terminal ileitis suspected to be infectious in origin.

Case Description/Methods: A 26 year-old male with a history of recent TIA while deployed to Kuwait was admitted for a three day history of fever with headache without associated gastrointestinal symptoms. Vital signs were remarkable only for fever to 102 degrees F. Neurologic and abdominal examination revealed no abnormalities and initial lab work was unremarkable. CT scan on admission incidentally revealed nodular wall thickening of the terminal ileum (TI) with adjacent mesenteric lymphadenopathy. Over the course of admission, the patient developed progressive mild leukopenia and thrombocytopenia. Infectious and hematologic work-up, including lumbar puncture, blood and urine cultures, hypercoagulable evaluation, peripheral flow studies and bone marrow biopsy were unrevealing. Colonoscopy was notable for edema and erythema of the ileocecal valve as well as a patch of nodular friable mucosa in the distal TI. Biopsies were negative for EMV, CMV, fungal elements and dysplasia but did demonstrate cryptitis and mild crypt architectural distortion. Colonoscopy performed 6 weeks later showed endoscopic improvement. Repeat biopsies were still notable for active terminal ileitis but again negative for the aforementioned processes. Given interval resolution of the patient’s fever and lab abnormalities with endoscopic improvement, we suspect the etiology for his terminal ileitis was infectious in origin. Follow-up colonoscopy is planned to ensure complete resolution.

Discussion: Terminal ileitis has a broad differential diagnosis and is not always representative of underlying CD. Alternate causes of terminal ileitis include lymphoma, NSAID use and infections such as Yersiniosis and intestinal tuberculosis. In this young male with recent TIA, unexplained fevers with cytopenias, and prominent mesenteric lymphadenopathy, there was initial concern for lymphoma. Ultimately, the patient demonstrated clinical improvement without intervention, suggesting a self-limited, possibly viral infection. This case highlights the importance of having a broad differential for terminal ileitis with thorough diagnostic evaluation, particularly when the patient presentation and clinic course is not consistent with common causes such as CD, as the misdiagnosis may lead to unnecessary treatment exposure and procedures.


Disclosures:


Natalie E. Mitchell, MD¹, Jerome Edelson, MD¹, Nicole M. Harrison, MD². P2544 - Terminal Ileitis: It’s Not Always Inflammatory Bowel Disease, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.