This is a peripheral adenocarcinoma of the lung. Adenocarcinomas and large cell anaplastic carcinomas tend to occur more peripherally in lung. Adenocarcinoma is the one cell type of primary lung tumor that occurs more often in non-smokers and in smokers who have quit. If this neoplasm were confined to the lung (a lower stage), then resection would have a greater chance for cure. The solitary appearance of this neoplasm suggests that the tumor is primary rather than metastatic.