What is Ovarian Teratoma?
Ovarian teratoma is a germ cell tumor or mass that develops inside the ovaries. Germ cells are the type of cells that help form the male and female reproductive organs.
Ovarian teratoma contains distinct tissue from the three germ cell layers, which are the ectoderm, endoderm, and mesoderm. A mature teratoma may contain:(1)
- Thyroid tissue
Amongst the different types of teratoma, the mature cyst teratoma is the most common. These are known as dermoid cysts.
Types of Ovarian Teratoma
Ovarian teratomas are classified into three categories:
- Mature Cystic Teratoma: There account for 20% of all the germ cells tumors of the ovaries and are usually not benign.(1) They can be removed surgically but can reoccur.
- Immature Teratoma: These tumors contain different types of cells, most of which may look abnormal under a microscope. These are most likely to be malignant and can spread to other areas of the body.(2)
- Monodermal Teratoma: These tumors may have:
- Neural tumors growing on the nerve tissue,
- Struma ovarii containing thyroid tissue
- Carcinoid tumors containing tissues that help in sending messages throughout the body.
Causes of Ovarian Teratomas
The exact cause of ovarian teratoma is still unknown but there are several theories given by the researcher, stating:(1)
- These tumors form from the unfertilized ovum, or egg after meiotic division, a division in which the parent cell reduces its chromosome by half to produce four gametes.
- They can occur due to abnormality during the three early stages of the fertilized egg.
The exact cause is not known but there are certain risk factors identified for mature cystic teratomas. These include:
Symptoms of Ovarian Teratomas
Most mature cyst teratomas may not cause any symptoms in the beginning. If symptoms show up, they may include:
- Abnormal growth of a tumor that is noticeable
- Gastrointestinal symptoms
- Increase in the urge to urinate
In severe cases, the ovarian teratomas may lead to:
Diagnosis of Ovarian Teratoma
- A mature cystic teratoma may remain undiagnosed until a mass is discovered in a routine examination.
- If there is ovarian torsion, a person might experience sudden symptoms and it could be due to ovarian teratoma.
- Once a teratoma is detected other imaging tests may be ordered. The most preferred test is transvaginal ultrasound.
Treatment of Ovarian Teratoma
Most cases of mature cystic ovarian teratomas can be treated successfully while preserving the ovaries. There are chances of tumor recurrence in 2-10 years, even with successful treatment.
The management of noncancerous ovarian teratomas includes:
Surveillance: This option works for people who want to get pregnant or are pregnant and have a small cyst with slower growth.
Surgical Procedure: Laparoscopic surgery is recommended for people with smaller cysts. Oophorectomy or removal of the ovary is recommended for those who have undergone menopause and have multiple cysts.
If an ovarian teratoma turns cancerous, the following treatment methods may be recommended:
If the ovarian teratoma is of immature type, the treatment would depend on the stage of the tumor. There may be complete removal of the tumor along with the surrounding tissue in the early stage of cancer. Chemotherapy may be recommended for more advanced stages if the doctor thinks cancer still persists.
Outlook for Ovarian Teratoma
A non-cancerous mature cystic teratoma has a good success rate post-treatment. The doctors remove the teratoma with laparoscopic surgery. There are chances of recurrence of teratoma within 2-10 years.
If the mature cystic teratoma turns into cancer, the survival rate is very low. A study described the survival rate of ovarian teratoma to be 2 years in 53 percent of cases and 5 years in 48.4 percent of cases.(3)
There is a poor outcome in advanced stages of cancer. According to a study done in 2016, the 5-year survival rate of cancerous ovarian teratomas is 98.3% in stage 1, 93.2% in stage 2, 82.7% in stage 3, and 72% in stage 4.(4)
A person may not realize suffering from ovarian teratoma as there are no symptoms According to the Centers for Disease Control and Prevention, all females between 18-65 years, who are sexually active should get a mandatory pelvic exam and a Pap smear in one year.(5) The ovarian teratoma may be discovered during the pelvic exam.
Also, someone experiencing sudden abdominal pain, nausea and vomiting should consult a doctor.