Teratomas often contain well-differentiated cells which can result in tissues growing in a teratoma which are quite different to the surrounding tissue - ovarian teratomas have been known to grow hair and teeth. Such a benign cystic teratoma is often termed a dermoid cyst. Testicular teratomas are generally less well-differentiated, and have a worse prognosis (chances of recovery are not as high).
See also
- Testicular cancer
- Ovarian cancer