When your child is diagnosed with cancer, it can feel overwhelming. This phase involves finding out if your child has cancer, and determining the type of cancer they have. Cancer in children can be difficult to diagnose, as many symptoms are similar to those caused by less serious conditions, or injuries. This means that your child will need multiple tests and medical appointments before you receive confirmation that your child has cancer.

If your doctor thinks your child has non-Hodgkin lymphoma, your child may have the following tests:

  • medical history and physical exam
  • blood tests
  • medical imaging, such as:
    • chest X-ray
    • ultrasound
    • computed tomography (CT) scan
    • magnetic resonance imaging (MRI)
    • positron emission tomography (PET) scan
  • biopsy of the cancer
  • lumbar puncture (spinal tap)
  • Collection of associated fluid produced by the lymphoma- paracentesis or thoracentesis (a thin, hollow needle collects fluid from either the belly or chest cavity to examine under a microscope)
  • bone marrow aspiration and biopsy.

Our section, How is cancer diagnosed? explains these tests in more detail.



Doctors use staging to describe how much the cancer has grown. Some of the tests for non-Hodgkin lymphoma will also help to stage the tumour. Staging measures:

  • where the tumour is
  • how big the tumour is
  • what nearby organs it affects
  • if the cancer has spread to other parts of the body.

Your doctor will use this information to choose the best way to treat the disease. Staging will also give the doctor an idea of how well these treatments are likely to work (prognosis). How doctors assess the stage and extent of disease varies. They often describe non-Hodgkin lymphoma in four stages:

  • Stage I – the lymphoma is either a single tumour (not in the lymph nodes) or is in the lymph nodes in a single part of the body. The lymphoma is not in the chest or belly.
  • Stage II – the lymphoma is not in the chest, and is one of the following:
    • a single tumour, and in nearby lymph nodes in one part of the body
    • more than one tumour and/or involves more than one set of lymph nodes on the same side of the body. These can be either both above or both below the diaphragm, which separates the chest and the abdomen.
    • in the digestive tract (e.g. the intestines or stomach) and doctors can remove it during surgery. Lymph nodes may or may not also have lymphoma cells.
  • Stage III – the lymphoma:
    • started in the chest
    • started in the belly but has spread too far for doctors to completely remove with surgery
    • is next to the spine (and may also be in other places)
    • is more than one tumour or occurs in more than one set of lymph nodes on both sides of the diaphragm (both above and below)
  • Stage IV – the lymphoma is in the brain, spinal cord or bone marrow when doctors first diagnose it. If cancer cells make up more than 25% of the bone marrow, Stage IV non-Hodgkin lymphoma may be reclassified as acute lymphocytic leukaemia.