Teratoma. Light micrograph (LM) of a section through an ovary showing a dermoid, or teratoma, ovarian cyst (centre). This is a benign (non-cancerous) cyst that arises from germ (sex) cells. Because germ cells develop into all the cells of the body, the cyst can contain a variety of different tissues, including bone, tooth and hair. This example shows keratinised epithelium with hair follicles. Treatment is with surgical removal of the cyst. Magnification: x50 when printed at 10 centimetres wide.