胆囊神经内分泌肿瘤（GB-NEN）是一种奇异的异质性肿瘤，起源于神经内分泌细胞，该细胞在胆囊粘膜上仅以微量存在，要么是由于未分化的干细胞的转化，慢性炎症并导致病理性上皮化生，要么是由于胆囊腺癌向神经内分泌癌转化。在所有胆囊恶性肿瘤中，胆囊神经内分泌肿瘤约占2.1％。一名41岁的女性患者出现右上腹疼痛和腹胀已有2周。对比CT显示胆囊底体部壁增厚不均，具有大的外生性组分，涉及肝脏的IV/V分段，周边强化和中央低密度坏死区。肝中裂和门静脉左支被增强病变、肿瘤血栓填充。她接受了左肝三叶切除术后辅助化疗。术后活检结果显示为差分不良的单发小细胞胆囊神经内分泌癌（GB-NEC）。切除的边缘未发现肿瘤，并且门静脉周围淋巴结未见肿瘤。术后六个月完成治疗后的随访PET-CT显示未见肿瘤复发或转移。她已完成手术后12个月且无症状。由于GB-NEC的发生率很低，关于其病因、发病机制、治疗和预后的数据很少。尽管转移早且最常见于淋巴结、肝脏、肺和腹膜，但GB-NEC中出现肿瘤血栓的报道很少。尽管大多数报告表明预后非常差，但本例显示，根治性手术后辅助化疗可以获得良好的短期效果。©该文章的作者（们）独家许可给日本临床肿瘤学学会，Springer Nature或其许可人（例如学会或其他合作伙伴）根据与作者（们）或其他权利持有人签订的出版协议享有本文的独家权利；根据该出版协议和适用法律规定，作者自行存档接受的手稿版本受到限制。

A gallbladder neuroendocrine neoplasm (GB‑NEN) is a bizarre heterogeneous neoplasm arising from neuroendocrine cells, which are present in minimal amounts on the GB mucosa either due to conversion of undifferentiated stem cells, chronic inflammation and resulting in pathological metaplasia or switching of GB adenocarcinoma to neuroendocrine one. Among all the GB malignancies, GB-NEN accounts for approximately 2.1%. A 41-year-old lady presented with right upper abdomen pain and distension for 2 weeks. Contrast CT showed heterogeneously enhancing wall thickening involving fundus-body of the GB with large exophytic component involving segments IV/V of liver, peripheral enhancement and central low attenuating necrotic areas. Middle hepatic and left branch of portal vein was filled with enhancing lesion, tumor thrombi. She underwent left trisectionectomy followed by adjuvant chemotherapy. Postoperative biopsy reported as poorly differentiated unifocal small cell GB-neuroendocrine carcinomas (GB-NEC). Resected margins were free of tumor with periportal lymph nodes negative for tumor. Follow-up PET-CT after six months of treatment completion shows no tumor recurrence or metastases. She has completed 12 months following the surgery and is asymptomatic. As the occurrence of GB-NEC is rare, there are little data regarding etiology, pathogenesis, treatment and prognosis of it. Even though metastasis is early and most frequent to lymph nodes, liver, lung and peritoneum, the presence of tumor thrombus in GB-NEC is rarely reported. Though most reports suggest very poor outcomes, radical surgery followed by adjuvant chemotherapy can yield good short-term results as seen in this case.© The Author(s) under exclusive licence to The Japan Society of Clinical Oncology 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.