A cyst is a closed sac containing either fluid or solid material. A mole is an area of the skin that is colored differently usually a dark brown. Its color comes from the same cells that give color to the skin, hair and eyes. Moles may be located anywhere on the body even on the scalp under the hair. They may vary in size and may be flat, raised or hairy.
Moles are important to watch as they can become cancerous in rare cases.
A skin tag is often confused with a mole. It may be flesh-colored or darker and look like a little flap of skin. Skin tags usually grow on the neck, underarm or groin areas, and under the breasts of women. They are harmless in that they never become skin cancer. However, if they become irritating, they may be removed by a doctor by either freezing with liquid nitrogen or cutting with a scalpel or scissors.