This is a medical question of type : stages 
 What are the stages of Childhood Hodgkin Lymphoma ? 
 Key Points
                    - After childhood Hodgkin lymphoma has been diagnosed, tests are done to find out if cancer cells have spread within the lymph system or to other parts of the body.    - There are three ways that cancer spreads in the body.    - Stages of childhood Hodgkin lymphoma may include A, B, E, and S.     - The following stages are used for childhood Hodgkin lymphoma:          - Stage I     - Stage II     - Stage III     - Stage IV        - Untreated Hodgkin lymphoma is divided into risk groups.
                
                
                    After childhood Hodgkin lymphoma has been diagnosed, tests are done to find out if cancer cells have spread within the lymph system or to other parts of the body.
                    The process used to find out if cancer has spread within the lymph system or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. Treatment is based on the stage and other factors that affect prognosis.    The following tests and procedures may be used in the staging process:          -   CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, such as the neck, chest, abdomen, or pelvis, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.     -   PET scan (positron emission tomography scan): A procedure to find malignant tumor cells in the body. A small amount of radioactive glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant tumor cells show up brighter in the picture because they are more active and take up more glucose than normal cells do. Sometimes a PET scan and a CT scan are done at the same time. If there is any cancer, this increases the chance that it will be found.    -   MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI). An MRI of the abdomen and pelvis may be done.    -   Bone marrow aspiration and biopsy : The removal of bone marrow and a small piece of bone by inserting a hollow needle into the hipbone or breastbone. A pathologist views the bone marrow and bone under a microscope to look for abnormal cells.
                
                
                    There are three ways that cancer spreads in the body.
                    Cancer can spread through tissue, the lymph system, and the blood:         - Tissue. The cancer spreads from where it began by growing into nearby areas.     - Lymph system. The cancer spreads from where it began by getting into the lymph system. The cancer travels through the lymph vessels to other parts of the body.     - Blood. The cancer spreads from where it began by getting into the blood. The cancer travels through the blood vessels to other parts of the body.
                
                
                    Stages of childhood Hodgkin lymphoma may include A, B, E, and S.
                    Childhood Hodgkin lymphoma may be described as follows:         - A: The patient does not have B symptoms (fever, weight loss, or night sweats).    - B: The patient has B symptoms.    - E: Cancer is found in an organ or tissue that is not part of the lymph system but which may be next to an area of the lymph system affected by the cancer.     - S: Cancer is found in the spleen.
                
                
                    The following stages are used for childhood Hodgkin lymphoma:
                    Stage I      Stage I is divided into stage I and stage IE.            -  Stage I: Cancer is found in one of the following places in the lymph system:                  - One or more lymph nodes in one lymph node group.       - Waldeyer's ring.       -  Thymus.       -  Spleen.                -  Stage IE: Cancer is found outside the lymph system in one organ or area.              Stage II     Stage II is divided into stage II and stage IIE.            -  Stage II: Cancer is found in two or more lymph node groups either above or below the diaphragm (the thin muscle below the lungs that helps breathing and separates the chest from the abdomen).     -  Stage IIE: Cancer is found in one or more lymph node groups either above or below the diaphragm and outside the lymph nodes in a nearby organ or area.              Stage III      Stage III is divided into stage III, stage IIIE, stage IIIS, and stage IIIE,S.            -  Stage III: Cancer is found in lymph node groups above and below the diaphragm (the thin muscle below the lungs that helps breathing and separates the chest from the abdomen).     -  Stage IIIE: Cancer is found in lymph node groups above and below the diaphragm and outside the lymph nodes in a nearby organ or area.     -  Stage IIIS: Cancer is found in lymph node groups above and below the diaphragm, and in the spleen.     -  Stage IIIE,S: Cancer is found in lymph node groups above and below the diaphragm, outside the lymph nodes in a nearby organ or area, and in the spleen.              Stage IV     In stage IV, the cancer:            - is found outside the lymph nodes throughout one or more organs, and may be in lymph nodes near those organs; or     - is found outside the lymph nodes in one organ and has spread to areas far away from that organ; or     - is found in the lung, liver, bone marrow, or cerebrospinal fluid (CSF). The cancer has not spread to the lung, liver, bone marrow, or CSF from nearby areas.
                
                
                    Untreated Hodgkin lymphoma is divided into risk groups.
                    Untreated childhood Hodgkin lymphoma is divided into risk groups based on the stage, size of the tumor, and whether the patient has B symptoms (fever, weight loss, or night sweats). The risk group is used to plan treatment.          -  Low-risk childhood Hodgkin lymphoma.    -  Intermediate-risk childhood Hodgkin lymphoma.    -  High-risk childhood Hodgkin lymphoma.