Gastric type 1 neuroendocrine tumours are considered to have low rates of proliferation and a good prognosis. We report here a patient with an aggressive well-differentiated high-grade gastric neuroendocrine tumour (gastric grade 3 NET), in a context of autoimmune gastritis. Consistent with grade 3 disease, the tumour had a Ki-67 proliferation index of 30%. Targeted next-generation sequencing identified variants of four genes, including a pathogenic ATM variant underlying the differentiation and metastatic potential of the tumour. Liver metastasis was diagnosed during follow-up, and the patient died after 6 years, due to disease progression.

中文翻译：

---

具有高级别特征的致病性 ATM 变异携带良好分化的侵袭性 1 型胃神经内分泌肿瘤 (G3 NET)：胃神经内分泌肿瘤临床和病理谱的新补充

胃 1 型神经内分泌肿瘤被认为具有低增殖率和良好的预后。我们在此报告一名患有侵袭性高分化高级别胃神经内分泌肿瘤（胃 3 级 NET）的患者，在自身免疫性胃炎的背景下。与 3 级疾病一致，肿瘤的 Ki-67 增殖指数为 30%。靶向二代测序鉴定了四种基因的变异体，包括一种致病性ATM变异体，该变异体是肿瘤分化和转移潜能的基础。随访期间确诊肝转移，6年后因疾病进展死亡。