The natural course of incidentally detected, small, subsolid lung nodules—is follow-up needed beyond current guideline recommendations?

Subsolid lung nodules are defined as focal lung lesions on computed tomography (CT) smaller than 3 cm with a ground glass component (1,2). This category includes nodules with only ground glass attenuation, called “pure ground glass nodules” or “nonsolid nodules”, and nodules with both a ground glass and a solid component, called “part-solid nodules” (1,2).