Pulmonary ground glass opacity tumor: a curable subtype of lung cancer when treated within the "surgical curative time window".

With the application of low-dose computed tomography (CT) screening for lung cancer in wider range of populations in Asia, a high prevalence of pulmonary ground glass opacity (GGO) tumors has been found in younger females or non-smokers. The detection rate of GGO tumors is as high as that of lung cancers in the traditional high-risk population. Therefore, the lung cancer screening should be applied in females or non-smokers, who have been recognized as a "high detection rate population" of lung cancers. Considering the indolent growth pattern of GGO tumors, two screening strategies including "younger age" and "lower frequency of CT scan" should be advocated for this population. The issue in management of GGO tumors is how to avoid over-diagnosis and over-treatment. Regular follow-up is essential for persistent GGOs, and a longer CT scan interval is warranted, which aims to avoid over-diagnosis. When surgery is considered for GGOs with growth, resection should be suggested within the "curative time window", which is defined as adenocarcinoma in situ (AIS) and minimal invasive adenocarcinoma (MIA) stages in pathology as well as pure GGOs <3 cm in radiology, because these patients can achieve a 100% survival rate, and can be really cured. Considering the favorable prognosis of GGO tumors, less invasive surgery including sublobar resection and selective or no lymph nodes dissection is also suggested to reserve more normal lung parenchyma and lymph nodes. Studies of radiologic and pathologic features for GGO tumors indicate the traditional concept that ground glass versus solid opacities tend to correspond respectively to pathologically lepidic versus invasive patterns is not always absolute. Application of whole mount pathologic sections helps to further understand the radiologic and pathologic correlation of GGO tumors.