Cyst
A cyst is a closed sac found somewhere within the body; it is usually fluid-filled. If we have a cyst, it means that we are holding onto an old issue by encapsulating it. The issue or emotion is represented by the fluid inside the cyst. The part of the body afflicted by the cyst gives us a clue as to the issue that is not being let go of.
Chuck Spezzano and Janie Ticehurst, Healing the Body Through Mind and Metaphor