A rare gastric neuroendocrine carcinoma coexisting with Brunner's gland adenoma: A case report.

Gastric neuroendocrine carcinoma (G-NEC) is a rare neoplasm known for its aggressive behavior and poor prognosis. Brunner's gland adenoma (BGA) is a rare benign proliferative lesion that develops most commonly in the duodenum. To the best of our knowledge, no cases of G-NEC coexisting with BGA have previously been reported. The present study therefore reports the first case of G-NEC combined with BGA. A 67-year-old female presented with upper abdominal discomfort. No distant metastases were detected upon pre-operative abdominal computed tomography imaging. The patient underwent a radical distal gastrectomy, D2 lymphadenectomy and Billroth I gastroenterostomy. The resected masses were histologically confirmed to be G-NEC and BGA, respectively. The patient did not receive neoadjuvant or adjuvant chemotherapy or radiotherapy, and remains alive with no evidence of metastasis or recurrence at four years post-surgery.