A case of early gastric mixed neuroendocrine-non-neuroendocrine neoplasm resected by endoscopic submucosal dissection

• Published in: Progress of Digestive Endoscopy Vol. 102; no. 1; pp. 80 - 82
• Main Authors: Morise, Takashi, Naito, Sakiko, Tadokoro, Kenichi, Madarame, Akira, Uchida, Kumiko, Kanda, Ryoya, Mugishima, Yuji, Kono, Shin, Itoi, Takao, Yamaguchi, Hayato, Yamanishi, Fumito, Matsumoto, Taisuke, Matsumoto, Sho, Kawai, Takashi, Fukuzawa, Masakatsu, Koyama, Yohei
• Format: Journal Article
• Language: English; Japanese
• Published: Japan Gastroenterological Endoscopy Society Kanto Chapter 30.06.2023
• ISSN: 1348-9844; 2187-4999
• DOI: 10.11641/pde.102.1_80

An 80-year-old man with a chief complaint of anemia underwent upper gastrointestinal endoscopy, and a 25-mm, white-toned, and elevated lesion was found on the posterior wall of the lower gastric body. Histopathological analysis revealed that the lesion was a mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN) comprising adenocarcinoma and neuroendocrine tumor. This patient had an intramucosal carcinoma with a G1-equivalent neuroendocrine neoplasm (NEN) component, and no apparent recurrence 6 months after endoscopic submucosal dissection (ESD) resection. MiNEN is a relatively new concept, which was modified in the 2019 World Health Organization (WHO) classification, and there is currently a lack of an established treatment and evidence for this disease. Reports of endoscopic resection of early gastric MiNEN are rare. We here report a case of successful endoscopic resection in a patient with MiNEN, together with a literature review.