[The diagnosis and treatment of G3 neuroendocrine tumors according to the new NCCN guideline].

Gastrointestinal pancreas (GEP) is the most common site of neuroendocrine neoplasms (NENs). In 2019, the World Health Organization (WHO) classification for GEP NET was updated to include a new category of well-differentiated high-grade (Ki 67>20%) GEP-NET G3, distinct from high-grade poorly differentiated neuroendocrine carcinoma (NEC). As a new category, NET G3 are considered a molecularly, radiologically, and prognostically distinct entity compared to NEC and NET G1/G2. The management of NET G3 remains a challenge awaiting future trials taking into consideration the unique characteristics of this new category. The latest NCCN clinical guidelines of neuroendocrine and adrenal tumors firstly gave the recommendation of diagnosis and treatment of G3 NET separately from NEC and G1/G2 NET. Hereon,we aim to summarize the management of G3 NET in combination with the new NCCN guidelines and the current evidences.胃肠胰是神经内分泌肿瘤最好发的部位。2019年WHO重新发布了胃肠胰神经内分泌肿瘤的分级标准，将细胞分化好、Ki67增殖指数>20%的肿瘤从原来的G3级神经内分泌癌（G3 NEC）分离出来，定义为G3级神经内分泌瘤（G3 NET）。G3 NET做为一个新的分级，在分子学、影像学以及预后方面均与NEC和G1/G2 NET表现不同，并且在诊治上仍有待探索。2021年神经内分泌肿瘤美国国立综合癌症网络（NCCN）指南也首次单独对G3 NET的诊治进行了推荐。在此，我们结合新版NCCN指南对G3 NET的诊治进行了总结。.