How LYmphoma Develops

Childhood non-Hodgkin lymphoma is a disease in which malignant (cancer) cells form in the lymph system.

The lymph system is part of the immune system and is made up of the following: 

• Lymph: Colorless, watery fluid that travels through the lymph system and carries white blood cells called lymphocytes. Lymphocytes protect the body against infections and the growth of tumors.
• Lymph vessels: A network of thin tubes that collect lymph from different parts of the body and return it to the bloodstream.
• Lymph nodes: Small, bean-shaped structures that filter lymph and store white blood cells that help fight infection and disease. Lymph nodes grow along the network of lymph vessels found throughout the body. Clusters of lymph nodes are found in the underarm, pelvis, neck, abdomen, and groin.
• Spleen: An organ that makes lymphocytes, filters the blood, stores blood cells, and destroys old blood cells. The spleen is on the left side of the abdomen near the stomach.
• Thymus: An organ in which lymphocytes grow and multiply. The thymus is in the chest behind the breastbone.
• Tonsils: Two small masses of lymph tissue at the back of the throat. The tonsils make lymphocytes.
• Bone marrow: The soft, spongy tissue in the center of large bones. Bone marrow makes white blood cells, red blood cells, and platelets.

Because lymph tissue is found throughout the body, childhood non-Hodgkin lymphoma can begin in almost any part of the body. Cancer can spread to the liver and many other organs and tissues.

There are four major types of childhood non-Hodgkin lymphoma.

The specific type of lymphoma is determined by how the cells look under a microscope. The 4 major types of childhood non-Hodgkin lymphoma are: 

• B-cell non-Hodgkin lymphoma (Burkitt and Burkitt-like lymphoma) and Burkitt leukemia.
• Diffuse large B-cell lymphoma.
• Lymphoblastic lymphoma.
• Anaplastic large cell lymphoma. 

There are other types of lymphoma that occur in children. These include the following: 

• Lymphoproliferative disease associated with a weakened immune system.
• Rare non-Hodgkin lymphomas that are more common in adults than in children.

Possible signs of childhood non-Hodgkin lymphoma include breathing problems and swollen lymph nodes.

These and other symptoms may be caused by childhood non-Hodgkin lymphoma. Other conditions may cause the same symptoms. A doctor should be consulted if any of the following problems occur: 

• Trouble breathing.
• Wheezing.
• Coughing.
• High-pitched breathing sounds.
• Swelling of the head, neck, upper body or arms.
• Trouble swallowing.
• Painless swelling of the lymph nodes in the neck, underarm, stomach, or groin.
• Fever for no known reason.
• Weight loss for no known reason.
• Night sweats.

Tests that examine the body and lymph system are used to detect (find) and diagnose childhood non-Hodgkin lymphoma.

The following tests and procedures may be used: 

• Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
• Biopsy: The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer.
• Immunohistochemistry study: A laboratory test in which a substance such as an antibody, dye, or radioisotope is added to a sample of cancer tissue to test for certain antigens. This type of study is used to tell the difference between different types of cancer.
• Cytogenetic analysis: A laboratory test in which cells in a sample of tissue are viewed under a microscope to look for certain changes in the chromosomes.
• Endoscopy: A procedure to look at organs and tissues inside the body to check for abnormal areas. An endoscope is inserted through an incision (cut) in the skin or opening in the body, such as the mouth. An endoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue or lymph node samples, which are checked under a microscope for signs of disease.
• Mediastinoscopy: A surgical procedure to look at the organs, tissues, and lymph nodes between the lungs for abnormal areas. An incision (cut) is made at the top of the breastbone and a mediastinoscope is inserted into the chest. A mediastinoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue or lymph node samples, which are checked under a microscope for signs of cancer.
• Anterior mediastinotomy: A surgical procedure to look at the organs and tissues between the lungs and between the breastbone and heart for abnormal areas. An incision (cut) is made next to the breastbone and a mediastinoscope is inserted into the chest. A mediastinoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue or lymph node samples, which are checked under a microscope for signs of cancer. This is also called the Chamberlain procedure.
• Thoracoscopy: A surgical procedure to look at the organs inside the chest to check for abnormal areas. An incision (cut) is made between two ribs and a thoracoscope is inserted into the chest. A thoracoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue or lymph node samples, which are checked under a microscope for signs of cancer. In some cases, this procedure is used to remove part of the esophagus or lung.
• Thoracentesis: The removal of fluid from the space between the lining of the chest and the lung, using a needle. A pathologist views the fluid under a microscope to look for cancer cells.
• Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram. The picture can be printed to be looked at later.
• 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.
• Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
• CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, 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.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) and treatment options depend on: 

• The age of the child.
• The type of lymphoma.
• The stage of the cancer.
• The number of places outside of the lymph nodes to which the cancer has spread.
• Whether the lymphoma has spread to the bone marrow or central nervous system (brain and spinal cord).
• Whether there are certain changes in the chromosomes.
• The type of initial treatment.
• Whether the lymphoma responds to initial treatment.
• The patient’s general health.

After childhood non-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. It is important to know the stage in order to plan treatment. Some of the tests that are used to diagnose childhood non-Hodgkin lymphoma are also used to stage the disease. The following tests and procedures may be used in the staging process: 

• Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
• Complete blood count (CBC).
• Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it.
• Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
• CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, 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.
• Bone marrow aspiration and biopsy: The removal of bone marrow, blood, and a small piece of bone by inserting a hollow needle into the hipbone or breastbone. A pathologist views the bone marrow, blood, and bone under a microscope to look for signs of cancer.
• Lumbar puncture: A procedure used to collect cerebrospinal fluid from the spinal column. This is done by placing a needle into the spinal column. This procedure is also called an LP or spinal tap.
• Bone scan: A procedure to check if there are rapidly dividing cells, such as cancer cells, in the bone. A very small amount of radioactive material is injected into a vein and travels through the bloodstream. The radioactive material collects in the bones and is detected by a scanner.
• 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).
• Endoscopy: A procedure to look at organs and tissues inside the body to check for abnormal areas. An endoscope is inserted through an incision (cut) in the skin or opening in the body, such as the mouth. An endoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue or lymph node samples, which are checked under a microscope for signs of disease.

There are three ways that cancer spreads in the body.

The three ways that cancer spreads in the body are: 

• Through tissue. Cancer invades the surrounding normal tissue.
• Through the lymph system. Cancer invades the lymph system and travels through the lymph vessels to other places in the body.
• Through the blood. Cancer invades the veins and capillaries and travels through the blood to other places in the body.

When cancer cells break away from the primary (original) tumor and travel through the lymph or blood to other places in the body, another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.

The following stages are used for childhood non-Hodgkin lymphoma

Stage I

In stage I childhood non-Hodgkin lymphoma, cancer is found: 

• in one group of lymph nodes; or
• in one area outside the lymph nodes. 

No cancer is found in the abdomen or mediastinum (area between the lungs).

Stage II

In stage II childhood non-Hodgkin lymphoma, cancer is found: 

• in one area outside the lymph nodes and in nearby lymph nodes; or
• in two or more areas above or below the diaphragm, and may or may not have spread to nearby lymph nodes; or
• to have started in the stomach or intestines and can be completely removed by surgery. Cancer may or may not have spread to certain nearby lymph nodes.

Stage III

In stage III childhood non-Hodgkin lymphoma, cancer is found:

• in at least one area above the diaphragm and in at least one area below the diaphragm; or
• to have started in the chest; or
• to have started in the abdomen and spread throughout the abdomen, and cannot be completely removed by surgery; or
• in the area around the spine.

Stage IV

In stage IV childhood non-Hodgkin lymphoma, cancer is found in the bone marrow, brain, or cerebrospinal fluid. Cancer may also be found in other parts of the body.

Childhood non-Hodgkin lymphoma is also described as low-stage or high-stage.

Treatment for childhood non-Hodgkin lymphoma is based on whether the cancer is low-stage or high-stage. Low-stage lymphoma has not spread beyond the area in which it began. High-stage lymphoma has spread beyond the area in which it began. Stage I and stage II are usually considered low-stage. Stage III and stage IV are usually considered high-stage.   

National Cancer Institute