As a result, an abscess—an enclosed pocket of pus and dead tissue—forms. In contrast, cysts aren't infections. The cells of the epidermis, or the outside layer of skin, constantly regenerate.

Bartholin cysts form when Bartholin gland ducts are blocked, leading to fluid accumulation inside of a sac. Learn about what ...

The cyst can also become infected and form an abscess, or a painful, puss-filled pocket. Once branchial cysts begin growing, doctors will advise immediate removal to prevent further infection.