Germ cell tumour
A germ cell tumour is a tumour which has started in the germ cells. Germ cells are those cells in the testis and ovary which normally develop into a baby in the womb. During development some of these cells become abnormal and later produce a tumour. This tumour usually develops in the ovary and testis but can also form in the abdomen, chest, lower spine or brain.
The tumour may be called by different names that describe where it started or what it looks like under the microscope, such as, yolk sac tumour, dysgerminoma and teratoma. These tumours may be benign (non-cancerous) or malignant (cancerous).
Who gets a germ cell tumour?
About 45 children develop a germ cell tumour in the UK each year. These tumours can occur at any age. The cause of germ cell tumours is unknown.
Signs and symptoms
The symptoms depend on where the tumour develops. Usually a lump appears which can be felt, for example: swelling of a testis, abdominal swelling or the lump may cause other symptoms.
Tests / investigations
We will need to carry out some tests to find out as much as possible about the type, position and size of the tumour. These tests include:
- Blood tests – germ cell tumours often produce hormones which can be measured in the blood; these are called ‘tumour markers’.
- Chest X-ray to see whether there is any tumour in the lungs.
- Ultrasound scan – this is usually done if your child has abdominal or testicular swelling.
- CT scan or MRI scan to tell us the exact position of any tumour within the body.
- Biopsy – a small operation, usually under general anaesthetic, to remove a small piece of the tumour; if the tumour is localised and can be easily removed then this will be carried out at diagnosis.
- Bone scan – this can tell us if the tumour has spread to the bones (metastases); a mildly radioactive dye is injected which is harmless, then a scan is taken.
Staging refers to the size of the tumour and whether it has spread. Knowing the stage of the cancer helps the doctors decide on the most appropriate treatment for your child. We use the following staging system for germ cell tumours:
- stage I: small localised tumour that has not spread
- stage II: larger localised tumour that has not spread
- stage III: localised tumour with involvement of lymph nodes
- stage IV: tumour has spread to other parts of the body.