A brain tumour is a lump in the brain which is caused when brain cells divide and grow in an uncontrolled way. What causes brain cells to start growing and dividing differently from healthy cells, is not yet understood. Brain tumours are quite complex - over 130 different types of 'high grade' (cancerous) brain tumours are known. Some of the most common brain tumours in children are:
Medulloblastoma usually develop in a part of the brain called the posterior fossa and may spread to other parts of the brain or spinal cord, through the cerebrospinal fluid (CSF) that surrounds the brain.
Ependymomas arise from ependymal cells that are found lining the ventricles of the brain (the fluid-filled spaces in and around the brain).
Diffuse Intrinsic Pontine Glioma or 'DIPG' is a high grade brain tumour these tumours tend to grow quickly and are more likely to spread to other parts of the brain or spinal cord. DIPGs originate in an area of the brain called the pons. The pons is an area deep within the lower part of the brain which is responsible for critical bodily functions, such as breathing, sleeping and blood pressure.
Lymphomas are cancers of lymphocytes that are normally found in the blood and lymph nodes of the body. The lymph nodes are part of the lymphatic system of the body and are part of the transport system with which the lymphocytes make their way around the body. Lymph nodes are special areas where lymphocytes can build up when they are preparing to fight infection. They normally build up and increase the size of the lymph node wherever the infection is to be found in the body. For instance, if you have a throat infection often the lymph nodes in the neck will become enlarged as the immune system fight that infection. When these lymphocytes become abnormal they can become lymphomas which are often found within the lymphatic system of the body. Often people will have lymph nodes that are enlarged, but will also have symptoms as a result of having lots of these abnormal lymphocytes. This can often lead to a person losing lots of weight (often >10%), have temperatures or fevers and night sweats when people notice they are sweating extensively at night.
In this cancer parent cells or stem cells (often called ‘blasts’) become abnormal and start producing lots of neutrophils and cells that would normally go on to make neutrophils. These cells can be found in the blood and in the bone marrow. In these leukaemias the abnormal cancer cells build up in the bone marrow and stop it doing its job of producing normal blood cells. This means that people can become anaemic (to have low red blood cells in the blood), have bruising or bleeding problems (if their platelet count is low) or get infections if their normal white blood cell numbers are low. Abnormal bloods cells are also normally seen in the blood and be seen when we look at a person’s blood sample under the microscope. As this is a problem of the bone marrow to make a diagnosis it is usually sensible to take a biopsy from the bone marrow- see bone marrow biopsy.
In this cancer parent cells or stem cells (often called ‘blasts’) that would normally go on to produce lymphocytes, become abnormal. These parent cells are normally found in the bone marrow and so in leukaemias, the abnormal cancer cells build up in the bone marrow and stop it doing its job of producing normal blood cells. This means that people can become anaemic (to have low red blood cells in the blood), have bruising or bleeding problems (if their platelet count is low) or get infections if their normal white blood cell numbers are low. Often once the bone marrow starts to fill up with the abnormal blasts cells they can spill over into the blood and be seen when we look at a person’s blood sample under the microscope. As this is a problem of the bone marrow to make a diagnosis it is usually sensible to take a biopsy from the bone marrow- see bone marrow biopsy. As with the normal lymphocytes we see, these leukaemias can be either B cell ALL or T cell ALL.
In this cancer parent cells or stem cells (often called ‘blasts’) that would normally go on to produce neutrophils and other blood cells become abnormal. These parent cells are normally found in the bone marrow and so in leukaemias the abnormal cancer cells build up in the bone marrow and stop it doing its job of producing normal blood cells. This means that people can become anaemic (to have low red blood cells in the blood), have bruising or bleeding problems (if their platelet count is low) or get infections if their normal white blood cell numbers are low. Often once the bone marrow starts to fill up with the abnormal blasts cells they can spill over into the blood and be seen when we look at a person’s blood sample under the microscope. As this is a problem of the bone marrow to make a diagnosis it is usually sensible to take a biopsy from the bone marrow.
Bone marrow is found inside all the big bones of the body. It is the factory that makes the cells we find in our blood. These include red blood cells that carry oxygen around the body, platelets that stop us bleeding when we injure ourselves and white blood cells that fight infection. White blood cells form a large part of the immune system and there are different types of white blood cells that have different jobs in fighting infection. Two important types are neutrophils that fight bacterial and fungal infections and lymphocytes that fight viral infections. Lymphocytes can be B lymphocytes (B cells) that make antibodies against infections or T lymphocytes (T cells) that can kill cells that are infected with viruses.
Germ cell tumours (GCT) in humans, germ cells develop into specialised cells needed for reproduction: sperm cells in boys and egg cells in girls. As a baby develops in the womb, the germ cells usually move to the ovaries or testes. So most patients diagnosed with a germ cell tumour have a tumour found in in the testes or the ovaries. Sometimes the germ cells fail to migrate to their proper location and settle in other parts of the body, where they can also develop into tumours and so less commonly can be found in the abdomen and pelvis, the part of the chest between the breastplate and the spinal column (the mediastinum), and the brain.
There are several different members of germ cell tumour family, depending on the characteristics of the cells involved. These include yolk-sac tumours, germinomas, embryonal carcinomas and teratomas.
Cancers that occur in the connective tissues of the body, such as muscle, fat, and fibrous tissue are usually considered sarcomas. The most common sarcomas in children are rhabdomyosarcoma (muscle) osteosarcoma (bone cells), and Ewing sarcoma (in or outside of bone).
