Pure ground-glass opacities (GGO) with a small consolidation area are mostly bronchioloalveolar carcinomas that have not yet become invasive, whereas a minority represents only inflammatory changes. Even if they are cancers, they are slow-growing and often remain unchanged for several years. There is no need for immediate resection of GGO lesions and a watchful waiting strategy is recommended. It seems that a lower-impact surgery (eg, wedge resection or segmentectomy) is curative for these lung cancers. Because high-resolution CT seems to predict noninvasive or minimally invasive GGO lung cancers with high reliability, less invasive treatments like radiofrequency ablation have greater appeal.