Lung cancer is a malignant tumor that has seriously endangered human life in the past 50 years, and its incidence and mortality rate are among the top malignant tumors, mainly because it cannot be detected early. Data show that (NSCLC) stage I 5-year survival is 60%-70%, stage II 40%-50%, and stage IIIA only about 25%.1 The early lung cancer imaging in high-resolution CT is dominated by isolated nodules (SPN) and ground glass-like changes (GGO). If isolated nodules in the lung can be detected early and the benignity or malignancy of the nodules can be determined, it can give early stage patients a chance of cure. Due to the widespread use of high-resolution thin-section CT scans in the last decade. The detection of isolated intrapulmonary nodules is gradually increasing, and intrapulmonary nodules (SPN) may be curable early stage lung cancer. Therefore, the value of detecting isolated intrapulmonary nodules and determining the benignity or malignancy of the nodules is highlighted. AAH and early lung cancer The incidence of 2AAH has been reported to be 2.8% in the population, 6.6% in the elderly group, and more likely to occur in patients with lung adenocarcinoma, ranging from 10% to 23.2%. 2004 AAH was first classified by WHO as a possible precursor lesion to lung adenocarcinoma. In our case, postoperative pathology of a nodule <10 mm reported both pulmonary adenocarcinoma and AAH in isolated pulmonary nodules. AAH is considered to be a precursor lesion for peripheral lung adenocarcinoma. It has been reported that AAH with EGFR mutations are more likely to develop into aggressive adenocarcinoma.2 EGFR and KRAS mutations play an important role in the development of lung adenocarcinoma, and some AAH contain EGFR or KRAS mutations. Although it is important to know the precise incidence of EGFR and KRAS to understand the pathology of lung adenocarcinoma, this issue has been quite controversial so far. EGFR mutations are common in lung adenocarcinoma and mutations are strongly associated with sensitivity to EGFR complexase inhibitors. On the other hand, lung adenocarcinoma also has mutations in the KRAS gene. lung adenocarcinoma with KRAS mutations, in contrast to lung adenocarcinoma with EGFR mutations, usually exhibit mucinous adenocarcinoma tissue characteristics, and KRAS mutations are more common in patients who are resistant to EGFR complexase inhibitors. smokers and former smokers, respectively. Thus, EGFR- and KRAS-mutated adenocarcinomas are considered to be two types of lung adenocarcinomas.3 Sakuma reported3 that 88% of pure non-mucinous adenocarcinomas and 75% of invasive adenocarcinomas accompanied by non-mucinous BAC developed EGFR mutations. These phenomena suggest that sustained EGFR signaling is due to activation of EGFR mutations is essential for the development and maintenance of lung adenocarcinoma. It is reasonable to assume that EGFR mutations in AAH promote the development of adenocarcinoma. In other words, AAH without EGFR mutations is likely to fail to develop into adenocarcinoma. This idea is consistent with clinical observations. However, we did not observe any differences in histology, tumor size and ploidy activity between AAH with and without EGFR mutations. More in-depth studies are needed to determine the differences between AAH with and without EGFR mutations. Isolated nodules with ground glass appearance (GGO) The prevalence of CT technology in clinical practice and the development of early scans of lung cancer using CT have improved the chances of detecting microscopic or ground glass nodules. Ground glass nodules may be found in malignant conditions, such as bronchoalveolar carcinoma, adenocarcinoma, and their early lesions, such as atypical adenomatous hyperplasia. The presence of a glassy nodule, over time, may strongly indicate an early stage of malignant disease, especially if the lesion is expanding or if there is a solid mass that keeps getting larger. Persistent vitreous nodules may also remain stable in shape. Glassy nodules are defined as hazy opacities that do not obscure the underlying bronchial and pulmonary vascular structures on high-resolution CT scans. A glassy nodule may be caused by partial air filling, by thickening of the air spaces due to inflammation, edema, fibrosis, or tumor proliferation, or by thickening of the air spaces due to partial air filling. lesions that appear as glassy nodules on CT may have a higher likelihood of developing malignant disease than solids. Malignant disease exhibiting those CT images include bronchoalveolar carcinoma, early adenocarcinoma. nakata4 et al. noted that the findings in their study regarding long-term ground glass nodules were due to tumors, which proved to be bronchoalveolar carcinoma (53.5%), a mixture of alveolar carcinoma and adenocarcinoma (25.6%), and atypical adenomatous hyperplasia (20.9%) in the pathological analysis. When the lesion contained a solid component in a ground glass nodule, the malignancy rate for ground glass nodular lesions was 93%. Henschke 5 et al. reported similar results based on their early lung cancer engineering data. 44 (19%) of 233 cases were accompanied by ground glass nodular lesions, and 15 (34%) of 44 were malignant. The malignant cases found in the ground glass nodules corresponded to 63% and 18% of cases with and without solid components, respectively. 33-60% of GGO were malignant between 11 and 20 mm in diameter. ＞The malignancy rate for >20 mm is 64-82% 6. The detection of isolated nodules in the lung has been common in the clinic, and it is sometimes difficult to determine the benignity or malignancy of pulmonary nodules, especially for nodules of about 10 mm in diameter. Vigilant observation and follow-up is necessary.