1. Isolated, purely ground glass nodules less than 5 mm in diameter do not require follow-up. This is especially true in the elderly because they represent pathologically atypical adenomatous hyperplasia and, in a few cases, adenocarcinoma in situ. 2. Isolated, pure ground glass nodules larger than 5 mm in diameter are reviewed after 3 months to see if the lesion disappears. If they persist, they are reviewed annually for at least 3 years. Pathologically atypical adenomatous hyperplasia, adenocarcinoma in situ and a small percentage of microinfiltrating adenocarcinoma should be alerted if the lesion increases in size or if the lesion becomes denser. 3, Isolated partially solid density ground glass nodules, especially those with solid component greater than 5 mm, should be considered as possible malignant lesions if the lesions are found to be increasing or unchanged on 3-month review. 4.Multiple ground glass nodules with clear margins less than 5 mm should be treated with a more conservative plan, and follow-up after 2 and 4 years is recommended. 5.Multiple pure ground glass-like nodules with at least one lesion larger than 5mm but without particularly prominent lesions are recommended to be reviewed after 3 months and with long-term follow-up for at least 3 years. 6, Multiple ground glass nodules with prominent lesions and major lesions requiring further management. On review after the first 3 months, more aggressive management of larger lesions is recommended if the lesions persist, especially if the solid component within the lesions is greater than 5 mm. This is the latest management guideline from the Fleischner Society, which states that “the most important issue that needs to be addressed at this time is the potential for overtreatment of ground glass nodules in the lung”. Personally, I think this is debatable, because a group of data shows that some solid density nodules have a 63% chance of malignancy, while pure ground glass nodules are up to 18% malignant.