[A Case of Esophagogastric Junction Adenocarcinoma with Neuroendocrine Differentiation].

Gastric cancer rarely contains neuroendocrine component. This mixed tumor is defined as neuroendocrine carcinoma (NEC), mixed adenoneuroendocrine carcinoma(MANEC)and so on according to the WHO classification. We report a patient with esophagogastric junction cancer with neuroendocrine differentiation(NED). The patient was 54-year-old man who diagnosed of esophagogastric junction cancer at the medical examination. Upper gastrointestinal endoscopy revealed a type 3 tumor at esophagogastric junction, and the pathological findings were poorly differentiated adenocarcinoma with focal positivity of chromogranin A. CT and FDG/PET revealed a metastatic regional lymph node. He had undergone proximal gastrectomy and lower esophagectomy, with dissection of D1+and double-tract reconstruction. Pathological findings revealed moderate to poorly differentiated adenocarcinoma containing chromogranin A-positive tumor cells. Neuroendocrine components were lower than 30%, and we diagnosed adenocarcinoma with NED. Standard treatment for gastric cancer with NED has not been established and more reports and reviews are required.