Clinical Insights into Duodenal Neuroendocrine Tumors: A Case Series

Abstract Duodenal neuroendocrine tumors (d-NETs) are rare neoplasms representing a small subset of gastrointestinal NETs. Due to their nonspecific symptoms, such as abdominal pain, vomiting, and weight loss, diagnosis is often delayed. This case series analyzes six patients with well-differentiated d-NETs, highlighting their clinical presentation, diagnostic evaluation, treatment strategies, and follow-up. Diagnosis was established through endoscopic biopsy, imaging modalities including computed tomography (CT) and positron emission tomography-CT, and confirmed by histopathology and immunohistochemistry. Tumors were graded using the World Health Organization/European Neuroendocrine Tumor Society classification, with Ki-67 indices ranging from 1 to 6%, corresponding to grade 1 or 2 NETs. Treatment included endoscopic or surgical resection in localized cases, while somatostatin analog therapy and peptide receptor radionuclide therapy were used in multifocal or metastatic disease. All patients were managed with an individualized, multidisciplinary approach, and demonstrated stable disease on follow-up. This study emphasizes the importance of early detection, accurate grading, and personalized management to optimize outcomes in patients with d-NETs.