👉 A broncholith is a hard, white, and often cystic structure that forms in the small tubes called the bronchi or alveoli. These structures are tiny collections of cells that line the walls of the lungs and help to remove mucus and other substances from the airways. Broncholiths can be either benign (meaning they do not cause any health problems) or malignant (meaning they may grow into a larger structure). They can appear in different parts of the body, including