Poorly differentiated neuroendocrine carcinomas (NECs) originating from the gastrointestinal (GI) tract are rare and very highly malignant disease with a poor prognosis. Poorly differentiated NECs most commonly arise in the esophagus and the large bowel; however, they may occur within virtually any portion of the GI tract. It is known, however, that they do not typically occur in the small intestine. A 21-year-old woman visited an emergency room with acute abdominal pain that commenced 2 days prior to her presentation. Thereafter, a computed tomography (CT) scan was notable for a small-intestine perforation, and huge masses were observed in the small intestine and the mesentery. The mass that was located at the ileum site is approximately 100 cm above the ileocecal (IC) valve, and while it is located on the anti-mesenteric border and it seems that luminal narrowing had occurred, an obstruction is absent. Also, a same-nature mass is on the mesentery. The pathologic reports confirmed a small-cell-type NEC with a mass size of 7.5 × 6.5 cm. The mitotic count is up to 24/10 high-power fields (HPFs), the results of the immunohistochemical stain are positive for CD56 and synaptophysin, and the Ki-67 level is 50%. %. After the operation, she was treated with Etoposide-Cisplatin (EP) chemotheraphy. Stable disease was seen during Etoposide-Cisplatin chemotheraphy. Liver metastasis was also confirmed after chemotheraphy. Additionally, Irinotecan and cisplatin were used for 3 cycles, but progression of disease, neutropenic fever, thrombocytopenia, general weakness persisted. Eventually, she died 1 year and 6 months after surgery. Ileum-located NECs are diagnosed very rarely. The most common locations for these tumors along the GI tract are the esophagus and the large intestine, but they can arise anywhere. The prognosis for NECs is poor due to the metastatic disease of most patients at the time of diagnosis. The role of adjuvant treatment requires further evaluation for the attainment of a better understanding of the overall treatment effect.

中文翻译：

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回肠小细胞神经内分泌癌：病例报告及文献复习

源自胃肠道（GI）的分化差的神经内分泌癌（NEC）很少见，而且是高度恶性的疾病，预后较差。分化差的NEC最常见于食道和大肠。然而，它们实际上可能发生在胃肠道的任何部分。但是，众所周知，它们通常不会在小肠中发生。一名21岁妇女在就诊前两天就开始了急腹症急诊室。此后，计算机断层扫描（CT）扫描显示出小肠穿孔，并且在小肠和肠系膜中观察到巨大的肿块。位于回肠部位的肿块位于回盲（IC）瓣上方约100 cm，虽然它位于反肠系膜边界，并且似乎发生了管腔变窄，但没有梗阻。同样，同一性质的肿块也在肠系膜上。病理报告证实小细胞型NEC的大小为7.5×6.5 cm。有丝分裂计数高达24/10高倍视野（HPFs），免疫组化染色结果对CD56和突触素为阳性，Ki-67水平为50％。％。手术后，她接受了依托泊苷-顺铂（EP）化疗。在依托泊苷-顺铂化学疗法中观察到稳定的疾病。化疗后也证实了肝转移。此外，使用伊立替康和顺铂治疗3个周期，但疾病进展，中性粒细胞减少，血小板减少，全身无力持续存在。最终，她在手术后1年零6个月死亡。位于回肠的NEC很少被诊断出来。这些肿瘤在胃肠道中最常见的位置是食道和大肠，但它们可以在任何地方出现。由于诊断时大多数患者的转移性疾病，NEC的预后很差。辅助治疗的作用需要进一步评估，以更好地了解总体治疗效果。