What does medical nodule mean?

Literally, a simple nodule has only one meaning of tissue protrusion, which refers to the phalanx. But in medicine, some mass cysts formed by connective tissue degeneration, inflammation, autoimmunity and new organisms can also be called nodules; Cystic lesions formed by multiple severe acne can be called nodules; Glandular hyperplasia in some parts can also be called nodules (thyroid nodules, breast nodules, etc.). If the subject is an exam noun, the first sentence will do.