P3043 - Small Bowel Neuroendocrine Tumor

Swetha Tummala, ¹, Natalie Patel, MD², Khoi Tran, MD³, Sanjeev Tummala, MD^3
1Boston University School of Medicine, Saratoga, CA; ²El Camino Health, Mountain View, CA; ³Palo Alto Medical Foundation, Mountain View, CA

Introduction: Neuroendocrine tumors (NETs) are epithelial tumors that arise from neuroendocrine cells of the digestive system. Within the digestive system, the majority occur in small intestine (45%). Diagnosis is usually made accidentally during a routine workup or from the patient experiencing symptoms from the tumor. We report a difficult-to-diagnose unsuspected NET of the ileum in a young, otherwise healthy individual.

Case Description/Methods: A 57-year-old female with a history of hypertension and hyperlipidemia presented to the emergency department with multiple episodes of dark stools one day prior to admission. A CT angiogram showed high density fluid in the small bowel with no active bleeding. Overnight, the patient had a near syncopal episode. A repeat CT angiogram showed active bleeding within the small intestine. However, on angiogram, no active bleeding was noted. The following day, an MR enterography showed thickening of the segment of the small intestine that had shown active bleeding on the repeat CT angiogram. During laparoscopy, the surgeon identified what felt to be a tumor in the distal ileum. Pathology revealed a well-differentiated neuroendocrine tumor (Image 1).

Discussion: NETs are the most common type of small bowel neoplasms. They are divided into duodenal NETs and distal NETs of the jejunum and ileum. Lymph node metastasis occurs in about 60% of cases of duodenal NET. Liver metastasis occurs in less than 10% of duodenal NET cases and about 20% of cases of distal NET of the jejunum and ileum.

The stage of the disease has a large impact on prognosis. The 10-year survival rate is 95% for patients with localized NETs and 10% for those with distant metastasis. Distal NETs of the jejunum and ileum have a poorer prognosis because of their tendency to metastasize. The annual incidence of NETs has increased over the past five years to forty to fifty cases per million, largely due to better diagnostic tools. For duodenal NETs, upper gastrointestinal endoscopy with biopsy is the most sensitive diagnostic test. Several genetic markers are being evaluated as diagnostic tools.

Treatment depends on the size of the NET. Small (≤ 1 cm) duodenal NETs can be resected endoscopically. Larger duodenal NETs (≥ 2 cm) or lymph node metastasis should be treated surgically. Systemic chemotherapy is not recommended for well-differentiated NETs.

In conclusion, this case describes difficulties in diagnosing NETs of the ileum and highlights the need for improvements in diagnosis and management of NETs.



Disclosures:


Swetha Tummala, ¹, Natalie Patel, MD², Khoi Tran, MD³, Sanjeev Tummala, MD³. P3043 - Small Bowel Neuroendocrine Tumor, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.