Tubular adenocarcinoma with HER2 score of 3 + was identified by pathological examination of station no. 105 obtained by endoscopic ultrasound guided fine needle aspiration and a clinical diagnosis of Siewert type II esophagogastric junction adenocarcinoma of HER2-positive (T2N0M1) was made. The gene discussed is ERBB2; the disease is gastroesophageal junction adenocarcinoma.