Acute lymphoblastic leukaemia (ALL) is a form of cancer that affects blood-producing cells in the bone marrow. It happens when these cells don’t mature properly, and grow too fast.
The word ‘acute’ means developing quickly, while ‘lymphoblastic’ refers to the type of white blood cell it affects.
When your child is healthy and everything’s working normally, the lymphoid blast cells in your child’s bone marrow mature into fully formed white blood cells called lymphocytes.
All kinds of cancers involve changes in genes in the affected cells. In a child with ALL, a change occurs that means these lymphoid blast cells don’t mature properly and become cancerous. These cancerous cells collect inside the bone marrow, which means there isn’t room for enough normal blood cells to be made. This is what causes most of the signs and symptoms of ALL.