A dermoid cyst is a type of teratoma, a tumor named from the Greek word teras, meaning “monster.” These usually benign masses contain developmentally mature cells of tissues found in the human body such as skin, hair, teeth, and bone. This specimen was removed in 1884 from a 23-year-old woman, which is an age typical of a patient with this condition. Dermoid cysts of the ovaries are thought to be present at birth and grow for decades. They are usually discovered in a woman's reproductively mature years when the cysts grow large enough to become painful or otherwise disruptive.