Ishikawa Akira, Tanaka Hidenori, Yamashita Ken, Oka Shiro, Mii Shinji
Department of Molecular Pathology, Graduate School of Biomedical and Health Sciences Hiroshima University Hiroshima Japan.
Department of Gastroenterology, Graduate School of Biomedical and Health Sciences Hiroshima University Hiroshima Japan.
JGH Open. 2025 Jun 26;9(7):e70208. doi: 10.1002/jgh3.70208. eCollection 2025 Jul.
Neuroendocrine neoplasms (NENs) of rectal origin containing non-neuroendocrine components are extremely rare. Additionally, there have been no previous reports of NENs accompanied by nonmalignant components. Herein, we report a case of an NEN accompanied by mucous cell glands that could not be regarded as a carcinoma.
A Japanese woman in her 30s underwent a colonoscopy that revealed a yellowish submucosal tumor-like protrusion in the rectum. Endoscopic findings suggested a high possibility of NEN; therefore, endoscopic mucosal resection was performed. Histopathologically, it was found that tumor cells had invaded beyond the muscularis mucosa into the submucosa. The tumor predominantly consisted of neuroendocrine tumor (NET) components with mucous cell glands observed in 5% of the tumor. The mucous cell glands were Periodic acid-Schiff-positive and immunohistochemically positive for CK20, whereas synaptophysin, CD56, and chromogranin A were negative. Based on the above findings, the pathological diagnosis was NET G1 with mucous cell glands.
This is the first reported case worldwide. Further discussion is needed to address the atypical nature of the glandular component and explore the differences and similarities with entities such as mixed neuroendocrine-non-NENs.
起源于直肠且包含非神经内分泌成分的神经内分泌肿瘤（NENs）极为罕见。此外，此前尚无NENs伴有非恶性成分的报道。在此，我们报告一例伴有黏液细胞腺且不能视为癌的NENs病例。
一名30多岁的日本女性接受结肠镜检查，发现直肠有一个淡黄色的黏膜下肿瘤样突起。内镜检查结果提示高度可能为NENs；因此，进行了内镜黏膜切除术。组织病理学检查发现，肿瘤细胞已侵犯至黏膜肌层以外进入黏膜下层。肿瘤主要由神经内分泌肿瘤（NET）成分组成，5%的肿瘤中可见黏液细胞腺。黏液细胞腺过碘酸-希夫染色阳性，细胞角蛋白20免疫组化阳性，而突触素、CD56和嗜铬粒蛋白A均为阴性。基于上述发现，病理诊断为伴有黏液细胞腺的NET G1。
这是全球首例报道病例。需要进一步讨论以解决腺性成分的非典型性质，并探索与混合性神经内分泌-非神经内分泌肿瘤等实体的异同之处。
