Ahmed Monjur
Division of Gastroenterology and Hepatology, Department of Internal Medicine, Thomas Jefferson University, Philadelphia, PA 19107, United States.
World J Gastrointest Oncol. 2020 Aug 15;12(8):791-807. doi: 10.4251/wjgo.v12.i8.791.
Gastrointestinal neuroendocrine tumors are rare slow-growing tumors with distinct histological, biological, and clinical characteristics that have increased in incidence and prevalence within the last few decades. They contain chromogranin A, synaptophysin and neuron-specific enolase which are necessary for making a diagnosis of neuroendocrine tumor. Ki-67 index and mitotic index correlate with cellular proliferation. Serum chromogranin A is the most commonly used biomarker to assess the bulk of disease and monitor treatment and is raised in both functioning and non-functioning neuroendocrine tumors. Most of the gastrointestinal neuroendocrine tumors are non-functional. World Health Organization updated the classification of neuroendocrine tumors in 2017 and renamed mixed adenoneuroendocrine carcinoma into mixed neuroendocrine neoplasm. Gastric neuroendocrine tumors arise from enterochromaffin like cells. They are classified into 4 types. Only type I and type II are gastrin dependent. Small intestinal neuroendocrine tumor is the most common small bowel malignancy. More than two-third of them occur in the terminal ileum within 60 cm of ileocecal valve. Patients with small intestinal neuroendrocrine tumors frequently show clinical symptoms and develop distant metastases more often than those with neuroendocrine tumors of other organs. Duodenal and jejuno-ileal neuroendocrine tumors are distinct biologically and clinically. Carcinoid syndrome generally occurs when jejuno-ileal neuroendocrine tumors metastasize to the liver. Appendiceal neuroendocrine tumors are generally detected after appendectomy. Colonic neuroendocrine tumors generally present as a large tumor with local or distant metastasis at the time of diagnosis. Rectal neuroendocrine tumors are increasingly being diagnosed since the implementation of screening colonoscopy in 2000. Gastrointestinal neuroendocrine tumors are diagnosed and staged by endoscopy with biopsy, endoscopic ultrasound, serology of biomarkers, imaging studies and functional somatostatin scans. Various treatment options are available for curative and palliative treatment of gastrointestinal neuroendocrine tumors.
胃肠道神经内分泌肿瘤是罕见的生长缓慢的肿瘤，具有独特的组织学、生物学和临床特征，在过去几十年中发病率和患病率有所上升。它们含有嗜铬粒蛋白A、突触素和神经元特异性烯醇化酶，这些是诊断神经内分泌肿瘤所必需的。Ki-67指数和有丝分裂指数与细胞增殖相关。血清嗜铬粒蛋白A是评估疾病负荷和监测治疗最常用的生物标志物，在功能性和非功能性神经内分泌肿瘤中均会升高。大多数胃肠道神经内分泌肿瘤是非功能性的。世界卫生组织于2017年更新了神经内分泌肿瘤的分类，并将混合性腺神经内分泌癌重新命名为混合性神经内分泌肿瘤。胃神经内分泌肿瘤起源于肠嗜铬样细胞。它们分为4种类型。只有I型和II型依赖胃泌素。小肠神经内分泌肿瘤是最常见的小肠恶性肿瘤。其中超过三分之二发生在距回盲瓣60厘米以内的回肠末端。与其他器官的神经内分泌肿瘤患者相比，小肠神经内分泌肿瘤患者经常出现临床症状，且更容易发生远处转移。十二指肠和空肠-回肠神经内分泌肿瘤在生物学和临床上有所不同。类癌综合征通常在空肠-回肠神经内分泌肿瘤转移至肝脏时出现。阑尾神经内分泌肿瘤通常在阑尾切除术后被发现。结肠神经内分泌肿瘤在诊断时通常表现为大肿瘤并伴有局部或远处转移。自2000年实施结肠镜筛查以来，直肠神经内分泌肿瘤的诊断越来越多。胃肠道神经内分泌肿瘤通过内镜活检、内镜超声、生物标志物血清学检查、影像学检查和功能性生长抑素扫描进行诊断和分期。胃肠道神经内分泌肿瘤的根治性和姑息性治疗有多种治疗选择。
