Early gastric cancer involving a pure enteroblastic differentiation component that was curatively resected via endoscopic submucosal dissection.

Gastric adenocarcinoma with enteroblastic differentiation (GAED) is a very rare variant of alpha-fetoprotein-producing gastric cancer (AFPGC). GAED is histologically characterized by cuboidal or columnar cells, which resemble those found in the primitive gut and have clear cytoplasm. In previously reported cases, GAED exhibit more aggressive behavior, as well as AFPGC, than conventional gastric cancer, such as marked lymphovascular invasion, lymph node metastasis, and liver metastasis. And also GAED was usually located in a deep mucosal layer and was covered by a conventional adenocarcinoma (CA) component. Based on these findings, GAED is considered to develop from CA during the process of tumor invasion and proliferation. We present a very rare case of early-stage GAED achieved curatively resected via endoscopic submucosal dissection, in which the lesion was composed of a pure enteroblastic differentiation component without a CA component.