Germ cell tumours of the ovary (ovarian teratoma)

This information is about a rare type of ovarian cancer. It should ideally be read with CancerBACUP’s general information about ovarian cancer.

The ovaries

The ovaries are two small oval-shaped organs, which are part of the female reproductive system (see diagram). Each month, in women of childbearing age, an egg leaves one of the ovaries and is released into the pelvic cavity where it then passes down the fallopian tube to the womb (uterus). If the egg is not fertilised it breaks down and is shed, along with the lining of the womb, as part of the monthly period.

The ovaries also produce the female sex hormones, oestrogen and progesterone. As a woman nears the ‘change of life’ (menopause) her ovaries make less of these hormones and her periods gradually stop.

Germ cell tumours

Germ cell tumours of the ovary are a rare type of ovarian cancer. Fewer then 1500 women are diagnosed with this type of cancer each year in the UK.

Germ cell tumours start in the egg- (ovum) producing cells of the ovary. They are different from the more common type of cancer of the ovary (epithelial cancer), and the treatment for germ cell tumours also differs. Some tumours produced by germ cells are benign (non-cancerous) and others are malignant (cancerous). Germ cell tumours tend to affect only one ovary and most are curable even if they are diagnosed at an advanced stage.

Different types of germ cell tumours

Dermoid cysts  These are benign tumours that are also known as mature teratoma. They are the commonest type of germ cell tumour. They are more commonly seen in young women but may also affect children and elderly women.

Dysgerminomas  This type of germ cell tumour is malignant and can more frequently affect both of the ovaries. It is more commonly seen in young women in their 20s.

Non-dysgerminomatous germ cell tumours  These tumours are also malignant and usually affect only one ovary. There are different types of non-dysgerminomatous germ cell tumours, some of which are very rare. The most common types are yolk sac tumours, immature teratoma and mixed primitive germ cell tumours. Other types include choriocarcinoma, gonadoblastoma and embryonal carcinoma. They are usually diagnosed in girls or young women.

Causes

The cause of germ cell tumours is unknown. Germ cells are a normal part of the ovary but sometimes changes in these cells make them divide and grow too quickly, resulting in the formation of a tumour.

Signs and symptoms

The most common symptoms include abdominal pain, a feeling of fullness or abdominal swelling, and sometimes an increasing need to pass urine. Some women may have irregular vaginal bleeding. These symptoms are common to many other conditions, but if you have any of them it is important to let your doctor know.

How it is diagnosed

Your doctor will carry out an internal pelvic examination to check the shape and position of the pelvic organs.

Several tests may be used to diagnose germ cell tumours of the ovary. One or more of the following may be carried out.

Blood tests  You may have a test to see whether chemicals called ‘tumour markers’ are being released into the bloodstream. These are useful in the diagnosis and treatment of certain types of germ cell tumour. The two main markers produced by germ cell tumours are AFP (alpha feta protein) and HCG (human chorionic gonadotrophin).

Ultrasound scan  A small device like a microphone, which produces sound waves, is rubbed over the abdomen. The sound waves are converted into a picture by a computer to clearly show the ovaries. Ultrasound scans can also be carried out vaginally. A small device (about the size of a tampon) is put into the vagina. Again the device produces sound waves that are converted into a picture by a computer.

CT (computerised tomography) scan  In this scan, several x-rays are taken and fed into the computer to build up a detailed picture of the size and position of the tumour.

Laparoscopy  Occasionally a simple operation called a laparoscopy is done. A small cut is made in the skin of the abdomen to allow the doctor to look at the ovaries and the surrounding area with a laparoscope. A laparoscope is a thin rigid tube that acts as a mini telescope. It can be inserted through the cut in the abdomen and by looking through the laparoscope the doctor can see the ovaries. The doctor may be able to remove the affected ovary in this way, or (more usually) by doing an operation called a laparotomy.

Once the ovary has been removed it is sent for examination under a microscope. In this way the doctor can tell if it is a germ cell tumour and what type it is.

Staging

The stage of a cancer is a term used to describe its size and whether it has spread beyond its original site. Knowing the particular type and the stage of the cancer helps the doctors to decide on the most appropriate treatment.

Cancer can spread in the body, either in the bloodstream or through the lymphatic system. The lymphatic system is part of the body’s defence against infection and disease. The system is made up of a network of lymph glands (also known as lymph nodes) that are linked by fine ducts containing lymph fluid. Your doctors will usually look at the lymph nodes close to the ovary to help find the stage of your cancer.

• Stage 1  The cancer is found in one or both of the ovaries.
• Stage 2  The cancer has spread within the pelvis and may also affect the womb or the fallopian tubes.
• Stage 3  The cancer has spread to the lymph nodes or other organs within the abdomen, such as the surface of the bowel.
• Stage 4  The cancer has spread outside the abdomen or to the liver.

If the cancer comes back after initial treatment, this is known as recurrent cancer.

Treatment

Improvements have been made in treating germ cell tumours and most women can now be completely cured. The treatment you will have depends on the site and type of germ cell tumour. Treatment will usually involve a combination of chemotherapy and surgery.

Surgery

The initial treatment for germ cell tumours is removal of the affected ovary and fallopian tube (unilateral salpingo-oophorectomy) during an operation known as a laparotomy. This is where a cut is made into the abdominal wall to allow the surgeon to remove the ovary.

In most cases it is only necessary to remove the affected ovary and the fallopian tube, which will not affect a woman’s ability to have children. Sometimes, however, it may be necessary to remove both ovaries, the fallopian tubes and the womb.

Chemotherapy

Chemotherapy is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells. They work by disrupting the growth of cancer cells.

A combination of chemotherapy drugs is given. Sometimes it is not necessary to follow the surgery with chemotherapy if the tumour is discovered at a very early stage. If chemotherapy is necessary it is usually given every three to four weeks, for six or more sessions of treatment.

Radiotherapy

Radiotherapy treats cancer by using high-energy rays that destroy cancer cells, while doing as little harm as possible to normal cells. Radiotherapy is sometimes given to treat particular types of germ cell tumours of the ovary.

Fertility

One of the main aims of treatment in young women is to preserve fertility, and this is taken into consideration when treatment is being decided upon. If you have had both of your ovaries removed or you have had radiotherapy to the ovaries you will be infertile. If only one of your ovaries has been removed the remaining ovary will continue to produce eggs. If you have chemotherapy treatment it may affect your remaining ovary and you may notice that your monthly periods stop or become irregular. Once the chemotherapy is finished, your periods should return to normal; however, this may take several months. Some older women may start their menopause (change of life) due to chemotherapy.

CancerBACUP has a section on fertility.

Follow-up

After your treatment is completed, you will have regular check-ups and possible scans or x-rays. These will probably continue for several years. If you have any problems, or notice any new symptoms in between these times, let your doctor know as soon as possible.

Your feelings

During your diagnosis and treatment you are likely to experience a number of different emotions, from shock and disbelief to fear and anger. At times these emotions can be overwhelming and hard to control. It is quite natural, and important, to be able to express them. Everyone has their own ways of coping with difficult situations; some people find it helpful to talk to friends or family, while others prefer to seek help from people outside their situation. Others prefer to keep their feelings to themselves. There is no right or wrong way to cope, but help is available if you need it. 

CancerBACUP has a section that discusses the emotional effects of cancer and how to deal with them.

References

This section has been compiled using information from a number of reliable sources including;

• Oxford Textbook of Oncology (2nd edition).
  Souhami et al. Oxford University Press, 2002.
• Cancer and Its Management (4th edition).
  Souhami and Tobias. Oxford Blackwell Scientific Publications, 2003.
• The Textbook of Uncommon Cancers (2nd edition). Raghavan et al. Wiley, 1999.

For further references, please see the general bibliography.