目的　探讨分泌血清素的恶性胰腺内分泌肿瘤的临床病理特点、诊断和预后。方法　对 1例分泌血清素的恶性胰腺内分泌肿瘤进行光镜、免疫组化观察并结合文献进行分析。结果　肿瘤细胞大小一致 ,圆形或多边形 ,呈实性成片状、巢索状排列 ,未见核分裂 ,胞质嗜酸性 ,向周围浸润 ,侵犯神经。淋巴结内见癌转移。NSE、CgA、Syn和serotonin阳性。结论　分泌血清素的恶性胰腺内分泌肿瘤来源于外分泌导管或腺泡上皮的Kultschitsky细胞 ,具有典型的神经内分泌肿瘤的组织学特征 ,常伴有类癌综合征 ,属低度恶性 ,病理诊断依赖于组织学、免疫组化并结合临床特征 Objective To investigate the clinicopathological features, diagnosis and prognosis of serotonin-producing malignant pancreatic endocrine tumors. Methods One case of serotonin-producing malignant pancreatic endocrine tumors was observed by light microscopy and immunohistochemistry combined with the literature. Results The tumor cells were uniform in size, round or polygonal in shape, and were arranged in the shape of nest cord. There were no nuclear fission, eosinophilic cytoplasm, infiltrated to the surrounding and nerve invasion. See lymph node metastasis. NSE, CgA, Syn and serotonin positive. Conclusions The serotonin-producing malignant pancreatic endocrine tumors originate from the exocrine ductal or acinar epithelial Kultschitsky cells. They have typical histological features of neuroendocrine tumors, often accompanied with carcinoid syndrome, which are of low grade and pathologically diagnosed depending on the tissue Learn, immunohistochemistry and clinical features