Duodenal Neuroendocrine Tumors and Upper Gastrointestinal Bleeding

Epidemiology and Characteristics of Duodenal NETs

Duodenal NETs represent approximately 3% of all gastrointestinal neuroendocrine tumors, with a relatively high rate of metastasis, showing approximately 60% nodal metastases and 30% liver metastases at presentation, as reported by the European Neuroendocrine Tumor Society 1, 2
About half of gastrinomas, a specific type of functional NET, arise in the duodenum, according to the European Neuroendocrine Tumor Society 3

Most gastroenteropancreatic NETs may present with non-specific symptoms including pain, nausea, vomiting, and in some cases, anemia due to intestinal blood loss, as stated by the European Society for Medical Oncology 3
Hormonal syndromes, mass effect from the primary tumor or metastases, are common clinical manifestations in symptomatic cases, as reported by the European Society for Medical Oncology 3

Upper endoscopy is the most appropriate initial diagnostic technique for investigation of upper GI bleeding, as recommended by the American College of Radiology 4, 5
Biopsy with immunohistochemical staining for chromogranin A and synaptophysin is essential for diagnosis, according to the European Society for Medical Oncology 6
Ki-67 (MIB-1) immunohistochemistry is mandatory to grade the tumor according to WHO classification, as stated by the European Society for Medical Oncology 6

For localized duodenal NETs, endoscopic resection is recommended if feasible, as suggested by the National Comprehensive Cancer Network 7
Other surgical options include transduodenal local excision with or without lymph node sampling and pancreatoduodenectomy, as recommended by the National Comprehensive Cancer Network 7