After surgery for ovarian teratoma, whether it can regrow is uncertain, because ovarian tissue can potentially develop such tumors. Ovarian teratomas can be benign or malignant. The recurrence rate of benign teratomas is very low after surgery, but there is still a possibility of regrowth. However, for malignant teratomas, also known as immature teratomas, surgery involves removing the affected ovary. The opposite ovary can be preserved if it is normal, depending on the patient's age, but regular follow-ups are necessary. If the patient is older, an extensive surgery for teratoma, which includes the removal of both the uterus and ovaries, might be required.