Immature Teratoma of the Ovary, from the CureRays guide library.

Immature teratoma is a rare ovarian germ-cell cancer of children and young women that is highly curable — usually with fertility-sparing surgery, sometimes followed by chemotherapy — while radiation is essentially not used.

What it is.

Immature teratoma is a rare type of ovarian germ-cell cancer that arises from the egg cells of the ovary. Unlike a mature teratoma (the common, benign 'dermoid cyst'), an immature teratoma contains tissue that looks young and developing under the microscope — most importantly, immature nerve (neural) tissue, the amount of which determines the tumor's grade. It mainly affects girls and young women. Most are found while still confined to one ovary, and the outlook is excellent. Treatment is built around surgery that, whenever possible, removes only the affected ovary and tube so that fertility and hormones are preserved. Chemotherapy is added for higher-grade or more advanced tumors. A practical point unique to germ-cell tumors is that after chemotherapy, leftover masses sometimes contain only mature, benign tissue (a phenomenon called 'growing teratoma syndrome'), which is removed surgically rather than treated with more chemotherapy.

How radiation treats it.

Radiation damages the DNA inside cancer cells so they can no longer divide, while healthy cells repair themselves more effectively. For immature teratoma, radiation is essentially not used — surgery and chemotherapy cure the great majority of patients and spare fertility. If radiation were ever needed for an isolated resistant spot, it would be delivered as short, painless sessions that leave no radioactivity in your body.

The ways we can treat it.

Radiation (essentially not used). Radiation is not part of standard treatment for immature teratoma. Highly effective surgery and chemotherapy have replaced it, which also helps protect fertility in young patients.

Stereotactic / focused radiation (rare). In the uncommon event of an isolated, chemotherapy-resistant deposit, precisely targeted radiation could be considered to control that single spot.

Palliative radiation (rare). Short courses of radiation can relieve symptoms in the very rare case of advanced, treatment-resistant disease.

Questions we hear often.

Can I still have children? Usually yes. Immature teratoma is typically treated with fertility-sparing surgery that removes only the affected ovary and tube, and the chemotherapy used (when needed) is generally compatible with future fertility. Your team can discuss fertility preservation options with you.

Is this the same as a dermoid cyst? No. A dermoid cyst (mature teratoma) is benign. An immature teratoma contains young, developing tissue and is a cancer — but it is highly curable, especially when found early.

Why might a mass grow during or after chemotherapy? Sometimes a teratoma's mature, benign tissue keeps growing even as the cancer is destroyed — this is called growing teratoma syndrome. It is not the cancer spreading; the right treatment is to remove the mass surgically and confirm it is benign.

This guide is informational only. It is not medical advice — please confirm anything here with your care team.