Gastric Type 1 Neuroendocrine Tumor in an Elderly Patient: A Case Report and Diagnostic Approach Review.

Gastric neuroendocrine tumors (G-NETs) are rare neoplasms with increasing incidence due to the broader use of endoscopy and improved diagnostic sensitivity. Type 1 G-NETs are the most common subtype and are typically associated with chronic atrophic autoimmune gastritis and hypergastrinemia. We present the case of an 84-year-old female patient admitted for the evaluation of progressive fatigue, weight loss, anorexia, and intermittent diarrhea. Initial workup revealed severe iron-deficiency anemia. Further testing demonstrated a positive interferon-gamma release assay (IGRA), with no evidence of active tuberculosis. Colonoscopy and gynecologic evaluation ruled out colorectal and adnexal malignancies. Esophagogastroduodenoscopy identified multiple raised vascular lesions in the gastric fundus and body. Histopathology confirmed a well-differentiated type 1 G-NET (grade 2, Ki-67 index 5%), associated with enterochromaffin-like cell hyperplasia and autoimmune atrophic gastritis. The patient was managed through multidisciplinary evaluation. Given the small size, low grade, and absence of metastasis, a conservative approach with endoscopic surveillance was chosen. While endoscopic resection or surgical interventions such as antrectomy or gastrectomy may be appropriate in selected cases, functional assessment and individualized decision-making remain essential, particularly in older adults with multimorbidity. This case highlights the diagnostic complexity of type 1 G-NETs in elderly patients and underscores the importance of tailored, multidisciplinary management strategies.