P1543 - Unusual Presentation of Neuroendocrine Tumor Mimicking Inflammatory Bowel Disease

Karan Sachdeva, MD¹, Gabrielle Sanford, MD², Maryam Mubashir, MD¹, Farhan Mohiuddin, MD³, Sudha Pandit, MD^1
1LSU Health, Shreveport, LA; ²Louisiana State University Health, Shreveport, LA; ³LSU Health, New Orleans, LA

Introduction: Neuroendocrine tumors (NETs) are a heterogeneous group of neoplasms originating from neuroendocrine cells scattered throughout the body. While they commonly arise in the gastrointestinal tract, they can manifest with a wide spectrum of clinical presentations, posing diagnostic challenges, particularly when mimicking other gastrointestinal conditions such as inflammatory bowel disease (IBD). The differentiation between NETs and IBD is crucial due to differences in management and prognosis.

Case Description/Methods: A 35 year old female presented with 2 years of chronic abdominal pain, predominantly in the epigastrium, associated with constipation and poor appetite. X-ray abdomen was inconclusive but CT abdomen revealed mild ileal wall thickening and tiny bilobar hepatic hypodensities with no other metastatic findings. Further evaluation during colonoscopy revealed edematous, erythematous and friable mucosa with inflammatory stricture at the terminal ileum (Image A and B), raising suspicion for inflammatory bowel disease. However, histopathological and immunohistochemistry of biopsy specimens unexpectedly revealed a well-differentiated neuroendocrine tumor (NET), Grade I (Image C and D). The tumor cells were positive for keratin AE1/3, Synaptophysin and Chromogranin. The patient underwent surgical intervention with jejunal resection of the mass and oncologic ileocecal resection, followed by ileocolonic side-to-side anastomosis. Pahtology reported pT3N1 with negative margins. During postoperative period, the patient reported significant improvement in symptoms, tolerance to diet and continues to follow up.

Discussion: This case highlights the diagnostic challenges posed by atypical presentations of NETs, which may mimic other gastrointestinal conditions. This underscores the importance of a multidisciplinary approach involving gastroenterologists, pathologists, and surgeons in the diagnosis and tailored management for timely interventions to improve patient care.



Disclosures:


Karan Sachdeva, MD¹, Gabrielle Sanford, MD², Maryam Mubashir, MD¹, Farhan Mohiuddin, MD³, Sudha Pandit, MD¹. P1543 - Unusual Presentation of Neuroendocrine Tumor Mimicking Inflammatory Bowel Disease, ACG 2024 Annual Scientific Meeting Abstracts. Philadelphia, PA: American College of Gastroenterology.