A part-solid lung nodule (PSN) or subsolid lung nodule is a morphological descriptor for a type of pulmonary nodule. It usually refers to a ground glass nodule with some solid component. They can be a manifestation of inflammation, infection, or fibrosis, but they can also be precursors of lung cancer, mainly adenocarcinoma (atypical adenomatous hyperplasia). Their overall malignant potential is considered higher than that of a comparatively size solid pulmonary nodule or a ground glass nodule. Notably, persistent lesions have a high likelihood of malignancy.