Refers to a sac-like structure in the body.
El médico me dijo que tenía una cista en el ovario que debía ser revisada.
The doctor told me I had a cyst on the ovary that needed to be checked.
La cista en su mano resultó ser benigno y no requerirá cirugía.
The cyst on his hand turned out to be benign and will not require surgery.