A 59-year-old man consulted our hospital because of an abnormal shadow on a chest computed tomography, located in the right lower lobe. Fluorodeoxyglucose-positron emission tomography showed abnormal uptake in the tumor suggesting lung cancer and right lower lobectomy was performed. Pathological the tumor was diagnosed as lung cancer comprising tall columnar cells. Immunohistochemical staining was positive for TTF-1, CK-7 and CK-20. Postoperative screening of the abdomen revealed no suspicious primary lesion in the colon and the tumor was diagnosed as a pulmonary enteric adenocarcinoma.