Surgical treatment of neuroendocrine tumors in the second portion of the duodenum: a single center experience and systematic review of the literature.

Lymph node metastases were common in association with both ampullary and non-ampullary NETs, and it was difficult to radiologically diagnose metastases. Additionally, there were no clinicopathological factors that could reliably predict the absence of lymph node metastases preoperatively. Therefore, to maximize the ability to achieve a curative resection, pancreaticoduodenectomy is considered appropriate in well-conditioned patients with NETs in the second portion of the duodenum. However, to further clarify the impact of lymph node dissection on survival after duodenal NET resection, a multi-institutional study with a large number of patients, thorough examination of lymph node metastasis, and a long observation period is warranted.