An Unusual Case of Duodenal Neuroendocrine Tumor

A 68-year-old female presented with a 5-day history of melena. The patient had a prolonged history of irregular aspirin use. Physical examination revealed pallor of the skin and mucous membranes, with the absence of abdominal tenderness. Laboratory investigations showed normocytic anemia (70.0 g/L) and positive fecal occult blood. Liver function, kidney function, and tumor markers were within normal ranges. Esophagogastroduodenoscopy revealed a submucosal lesion in the duodenal bulb, measuring approximately 2 cm × 2 cm and resembling a “doughnut,” with central ulceration and surrounding mucosal vascular dilation. Biopsy histopathology confirmed a G2-grade neuroendocrine tumor. Abdominal contrast-enhanced CT indicated thickening of the duodenal bulb wall with slight enlargement of surrounding lymph nodes. Subsequently, the patient underwent a distal gastrectomy with resection of the duodenal bulb. Postoperative pathology revealed the absence of vascular invasion and lymph node infiltration. Follow-up examinations, including gastric endoscopy and abdominal CT, revealed no signs of recurrence.