dermoid cyst
(DER-moyd sist)
A type of tumor that contains a cyst filled with tissues that are normally found in the outer layers of the skin, including sweat and oil glands. These may also contain elements of hair and teeth. Dermoid cysts can form anywhere in the body, but they usually form in the ovary, testes, the skin of the head, neck, face, or lower back, or in the central nervous system. Dermoid cysts are benign (not cancer) and tend to grow slowly. They are present at birth but may not be found until later in life. Dermoid cysts are a type of germ cell tumor called a mature teratoma.