A Rare Case of Grade I Duodenal Neuroendocrine Tumor Presenting with Upper Gastrointestinal Bleeding and Severe Iron Deficiency Anemia

Background

Duodenal neuroendocrine tumors (D-NETs) are rare neoplasms accounting for approximately 2–5% of gastroenteropancreatic neuroendocrine tumors. They are commonly asymptomatic and incidentally detected; however, ulcerated lesions may rarely present with vert gastrointestinal bleeding and severe iron deficiency anemia. CASE PRESENTATION Despite taking oral and parenteral iron supplements, a 62-year-old woman developed recurring melena and severe iron deficiency anemia that required transfusions. Microcytic hypochromic anemia with hemoglobin of 7.5 g/dL, decreased mean corpuscular volume, and peripheral smear results indicative of chronic blood loss were found in the laboratory assessment. Erosive pangastritis, a Helicobacter pylori-associated gastric ulcer, and over eight sessile and sub-pedunculated polypoidal lesions extending from the first to third parts of the duodenum were discovered during upper gastrointestinal endoscopy. Several of these lesions showed deep ulceration with active bleeding. Four bigger lesions underwent endoscopic band ligation. Several modestly hyper-enhancing duodenal polyps were seen on contrast-enhanced CT enterography; the biggest one was around 15 × 15 mm. Brunner gland hyperplasia with questionable neuroendocrine foci was revealed by histopathological analysis, however, a well-differentiated Grade I neuroendocrine tumor with widespread synaptophysin positivity and a Ki-67 proliferation index of 2% was verified by immunohistochemistry. With SUVmax values of 5.0 on early imaging and 10.0 on delayed imaging, Ga-68 DOTATOC PET-CT showed somatostatin receptor-positive multifocal duodenal lesions up to 1 cm in size. There was no indication of solid organ involvement, distant metastases, or locoregional lymphadenopathy.

Conclusion

This case illustrates a rare manifestation of multifocal Grade I duodenal neuroendocrine tumors linked to overt upper gastrointestinal hemorrhage, severe iron deficiency anemia, and Brunner gland hyperplasia. Accurate staging and prompt care are made possible by early detection employing a multidisciplinary approach that includes endoscopy, histology, immunohistochemistry, and somatostatin receptor imaging. This improves clinical results.