Germ cell tumour

Germ cell tumours are fast growing, 'malignant' tumours. They grow from cells that are involved in our growth when we are developing in the womb. Germ cells form part of the embryo and develop into the reproductive system.

Most germ cell tumours occur outside the brain, but those that do grow in the brain are most often in the area close to the pituitary gland and the pineal gland at the base of the brain. These are called 'intracranial germ cell tumours'. They are also called embryonal tumours.

There are two main types of intracranial germ cell tumour: non-secreting germinomas and secreting germ cell tumours. They can spread via the cerebro-spinal fluid around the brain and to the spine.

They represent around 1 - 2% of all brain tumours. About half of these occur in children and young adults (10 - 20 years old).

Symptoms of germ cell tumours

Germ cell tumours often block the flow of cerebro-spinal fluid (CSF) around the brain and spinal cord. This causes headaches and sickness and, as a result, these tumours are often picked up early when they are still small.

Diagnosing germ cell tumours

They also sometimes produce chemicals that can be picked up in blood tests (biomarkers) and this can also help to diagnose these tumours quickly.

A biopsy to give an exact diagnosis may be undertaken, or surgery used to treat hydrocephalus (excess water in the brain) caused by the tumour blocking the flow of cerebrospinal fluid. Occasionally surgery can be used to remove some of the tumour.

Treatment of germ cell tumours

Due to their location, they are usually treated with chemotherapy or a combination of radiation and chemotherapy, rather than surgery.