Teratomas are tumors that can contain different types of tissues, including hair, teeth, and even organs. They are usually found in the ovaries or testicles, but can also occur in other parts of the body. While most teratomas are benign, some can be cancerous. One interesting theory about teratomas is the “evil twin” theory. This theory suggests that teratomas are formed from cells that were originally meant to develop into a twin, but instead developed into a tumor. This is why teratomas can co

Four types of... - The New England Journal of Medicine