A 74 years old male was diagnosed 3 years ago with non small cell lung carcinoma. Accordingly, it was decided that no chemotherapy should be given at that stage. Year and a half later, a new SOL was found in right lung, and right pneumonectomy was performed. On pathology a well to moderately differentiated adenocarcinoma was found. Lymphatic invasion was identified in lung and mediastinum. A revision on previous specimen was performed and it was concluded that the tumor was morphologically different from the previous specimen.