Multiple endocrine neoplasms are a feature of multiple endocrine neoplasia (MEN) syndromes types 1, 2, 4, and 5. However, the ileum is not usually involved in these disorders. We report a series of patients with neuroendocrine tumors (NETs) involving both the pancreas and the ileum. We searched the laboratory information system and personal consultation records of the authors from 2019 to 2023 for patients who had neuroendocrine tumors (NETs) involving both the pancreas and ileum. In a series of 846 patients, we identified 4 patients with pancreatic and ileal NETs, 2 female and 2 male, ages 52 to 75. Two female patients had primary EC cell tumors of the ileum with metastasis to the pancreas that showed expression of CDX2 and serotonin similar to the ileal primary tumors. Two males had primary lesions in the 2 sites with different immunoprofiles; the ileal tumors expressed CDX2 and serotonin and were negative for ARX, whereas the pancreatic tumors expressed ARX, glucagon, and pancreatic polypeptide and were negative for CDX2 and serotonin. In both male patients, the nontumorous pancreas showed preneoplastic changes in the endocrine elements, suggesting germline predisposition to endocrine neoplasia. Testing for known genetic alterations underlying MEN syndromes has not identified a genetic alteration that can be implicated in the development of NETs in both pancreas and ileum. Our series indicates the rare occurrence of NETs in both the pancreas and ileum and emphasizes the importance of using the correct biomarkers to distinguish metastasis from primary neoplasms at the different sites. The rare occurrence of primary ileal and pancreatic NETs may represent a novel MEN syndrome with as yet unknown germline predisposition.

中文翻译：

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胰腺和回肠神经内分泌肿瘤：转移性疾病还是新型 MEN 综合征？


多发性内分泌腺瘤是 1 型、2 型、4 型和 5 型多发性内分泌腺瘤 （MEN） 综合征的一个特征。然而，回肠通常不参与这些疾病。我们报告了一系列涉及胰腺和回肠的神经内分泌肿瘤 （NETs） 患者。我们检索了 2019年至 2023年实验室信息系统和作者的个人会诊记录，以查找同时累及胰腺和回肠的神经内分泌肿瘤 （NETs） 患者。在 846 例患者的系列研究中，我们确定了 4 例胰腺和回肠 NET 患者，2 例女性和 2 例男性，年龄在 52 至 75 岁之间。2 例女性患者为回肠原发性 EC 细胞瘤，转移至胰腺，显示 CDX2 和 5-羟色胺的表达与回肠原发性肿瘤相似。2 例男性在 2 个免疫特征不同的部位有原发病灶;回肠肿瘤表达 CDX2 和 5-羟色胺，ARX 阴性，而胰腺肿瘤表达 ARX、胰高血糖素和胰腺多肽，CDX2 和 5-羟色胺阴性。在两名男性患者中，非肿瘤性胰腺的内分泌成分均表现出癌前变化，表明内分泌肿瘤的种系易感性。对 MEN 综合征的已知遗传改变的检测尚未确定可能与胰腺和回肠 NET 的发展有关的遗传改变。我们的系列表明 NET 在胰腺和回肠中都很少发生，并强调了使用正确的生物标志物来区分不同部位的转移和原发性肿瘤的重要性。罕见的原发性回肠和胰腺 NET 可能代表一种新型 MEN 综合征，其种系易感性尚不清楚。