Gastric neuroendocrine tumors in our institutions according to the WHO 2010 classification.

In 2010, World Health Organization classified gastric neuroendocrine tumor (NET) as follows: NET grade (G) 1, NET G2, neuroendocrine carcinoma (NEC). We reviewed 22 gastric NETs that were encountered in our institutions. Nine, 6, and 4 were NET G1, G2, and NEC, respectively. We also encountered 3 NET G3. NET G1 was treated with observation in 2 patients, endoscopic mucosal resection (EMR) in 3, and gastrectomy in 4 patients. No recurrence was experienced during a median of 53 months of follow-up. All NET G2 was treated with gastrectomy. No patient experienced recurrence during a median of 25 months of follow-up. NET G3 was treated with gastrectomy. One patient died of liver metastasis 52 months after gastrectomy. For NEC, gastrectomy was performed in 3 cases and no patients died of tumor-related death. We conclude that the prognoses of NET G1 and G2 were good. We also experienced long-term survivors of NEC. An accumulation of more patients is needed for further investigation.