Guidelines for the Investigation and Management of Ground Glass Nodules

The clinical significance of ground-glass nodules (GGNs) has been investigated in extensive clinical research for many years. The natural history of GGNs is known to be closely related to their size, proportion of solid components, and size progression over time. Based on these data, several guidelines for GGN management have been published worldwide. The indications for nonsurgical biopsy or surgical resection of GGNs are as follows: pure GGNs between 5 and 10 mm in size if they increase in size or show development of a solid component at follow-up, pure GGNs >10–15 mm that remain stable but persistent, part-solid nodules >8 mm persisting at follow-up, or part-solid nodules with a solid component >6 mm at follow-up. Newly updated data considering geographical or racial factors and recent developments in surgical techniques may improve the surgical indications for GGNs in the near future.