Well-differentiated Neuroendocrine Tumor (Carcinoid)
Type 3 neuroendocrine tumors are less common in the stomach (approx. 20% of all gastric NE tumors) and arise sporadically, without any clear etiologic factor. These lesions, which arise from enterochromaffin cells, are typically small but are highly aggressive and metastasize early and often. They commonly produce ectopic hormones.