An immature teratoma is a rare type of cancer which mainly affects females under the age of 20. It is an example of what is called a germ cell tumor. Germ cell tumors develop from eggs or sperm, and an immature teratoma arises in egg cells inside the ovary. It is different from a mature teratoma, which is a benign, or non-cancerous, growth found in women of child-bearing age. Although an immature teratoma is a malignant tumor, treatment with chemotherapy and surgery can sometimes be successful even after the cancer has spread.
Oncology researchers do not fully understand the causes of an immature teratoma, but there may be a genetic factor as the tumor is found more frequently in certain families. Symptoms of an immature teratoma may include swelling of the abdomen, pain, vomiting, or, with more advanced tumors, a lump which can be felt. Pain may occur suddenly or be present for a longer period of time. Sometimes the tumor may cause the ovary to twist round, cutting off its blood supply, and this can cause severe sudden pain.
Diagnosis of the tumor can be made using a computerized tomography, or CT, scan, together with blood tests to check for substances known as tumor markers which indicate cancer may be present. An immature teratoma is assessed in stages according to how far it has spread and graded to describe how aggressive it is. There are three possible grades, with grade one representing a tumor that grows slowly and has less chance of spreading, and grade three a tumor that increases its size rapidly and is more likely to spread. Stages of cancer range from one to four, with stage one being assigned to tumors which have not spread at all and stage four to those which have spread throughout the body.
Management of an immature teratoma generally involves surgery to remove the tumor and its associated ovary. As the other ovary may be left in place, this means that many women are still able to have children following treatment. During the operation, the surgeon is able to inspect the tissues around the teratoma and examine other organs for any signs that the cancer has spread. Samples of tumor tissue may be taken and analyzed to determine the grade of the teratoma. For cancers which have remained inside the ovary and which are only grade one, surgery may be the only treatment required.
Where a cancer has spread outside the ovary, it is not always necessary to remove it all at once as chemotherapy is given to shrink the tumor cells. If any cancer remains following chemotherapy, another operation may be needed to get rid of it. The outlook for a patient with an immature teratoma depends on the grade of the tumor and the extent of spread, but in many cases it is positive.