A rare early gastric mixed neuroendocrine-non-neuroendocrine neoplasm misdiagnosed as early gastric cancer.

Recently, mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) have attracted more attention. However, early gastric MiNEN is uncommon, and there are rare reports on the characteristics of it. As its clinical and endoscopic features are resemble to early gastric cancer (EGC), it can be easily misdiagnosed. The purpose of this article is to elaborate the endoscopic and pathological characteristics of early gastric MiNEN, which is of great significance for distinguishing it from EGC. A 67-year-old male patient underwent EGD revealing a 0-IIc+IIa lesion on the lesser curvature of the lower stomach body. The biopsy pathology indicated the lesion was an EGC. Endoscopic submucosal dissection (ESD) was subsequently applied to remove the lesion. According to postoperative pathological, the lesion was diagnosed as early MiNEN (tubular adenocarcinoma 50%, neuroendocrine carcinoma 50%), pT1b (submucosa 600 μm), pUL (1), Ly (0), v (1), pHM0, pVM0. And after that, surgical resection were added. A follow-up CT scan and endoscopy performed six months later revealed no metastasis or recurrence. This case highlights that early gastric MiNEN could mimic ECG. We deemed that ME-NBI combined with pathological biopsy could contribute to the identification of early gastric MiNEN.