Seronegative Alpha-Fetoprotein-Producing Early Gastric Cancer Treated with Endoscopic Mucosal Resection and Additional Surgery

A 67-year-old man visited our hospital for the treatment of gastric carcinoma. Endoscopic mucosal resection was performed, however, histological examination of the resected specimen revealed tumor invasion to the submucosal layer with vessel invasion. Immunohistological studies were carried out on resected specimens and part of the cancerous lesion showed a positive reaction for alpha-fetoprotein (AFP), but the serum AFP level was normal. Additional distal gastrectomy with lymph node dissection revealed lymph node metastasis although there was no apparent finding of lymph node swelling by preoperative diagnostic imaging. This patient remains alive without disease for 3 years after surgery.