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Types of childhood non-Hodgkin lymphoma
Childhood non-Hodgkin lymphoma (NHL) is a cancer that starts in lymphocytes. The 2 types of lymphocytes are B cells and T cells. Childhood NHL can start from B cells or T cells.
Childhood NHL can be divided into the 4 major types:
- Burkitt lymphoma
- Diffuse large B-cell lymphoma
- lymphoblastic lymphoma
- anaplastic large cell lymphoma.
About 35%–40% of all childhood NHLs are Burkitt lymphoma (also known as small non-cleaved cell lymphoma) and Burkitt-like lymphoma. They usually occur in children aged 5–15 years, and they are more common in boys.
Burkitt lymphoma is a type of B-cell lymphoma. It most often starts in the abdomen, but it can also start in lymphatic tissue in the head, neck or other parts of the body. It is a fast-growing cancer that often spreads to the bone marrow and the brain and spinal cord (called the central nervous system, or CNS).
Burkitt-like lymphoma cells look slightly different from Burkitt lymphoma when viewed under a microscope. They also have some features of diffuse large B-cell lymphoma. Burkitt-like lymphoma behaves like and is as aggressive as Burkitt lymphoma, so it is included with Burkitt lymphoma.
Lymphoblastic lymphoma makes up 25%–30% of all childhood NHLs. Lymphoblastic lymphoma is most common in teenagers, and it occurs in boys more often than girls.
Most lymphoblastic lymphomas start from T cells. They commonly develop as a mass in the chest, or mediastinummediastinumThe space in the chest between the lungs, breastbone and spine that contains the heart, great blood vessels, thymus, trachea (windpipe), esophagus and lymph nodes.. They can also occur in the tonsils or the lymph nodes of the neck or other parts of the body.
Some lymphoblastic lymphomas start from B cells. They often start in lymph nodes in the neck, skin or bones.
Lymphoblastic lymphomas are aggressive and can spread very quickly to the bone marrow, other lymph nodes, brain or the membranes around the lung or heart.
Diffuse large B-cell lymphoma
Diffuse large B-cell lymphoma (DLBCL) makes up 15%–20% of all childhood NHLs. It is most common in people 10–20 years of age.
DLBLC starts from B cells. It often occurs as a large mass in the chest, or mediastinum, which can lead to breathing problems. It can also start in the bones or in lymphatic tissue in the neck or abdomen. It grows slightly slower than other types of lymphoma but often is at an advanced stage at diagnosis. It is the most common type of NHL in children who have a pre-existing weakened immune system (called immunodeficiency).
Primary mediastinal B-cell lymphoma is considered a subgroup of DLBCL and makes up about 1%–2% of all childhood NHLs. It is mostly diagnosed in older teenagers. Primary mediastinal B-cell lymphoma starts in the chest, or mediastinum. It can affect the pericardiumpericardiumThe double-layered sac that surrounds the heart. It protects the heart and produces a fluid that acts like a lubricant so the heart can move normally in the chest. and the lungs and can cause decreased blood return to the heart (called superior vena cava syndrome).
Anaplastic large cell lymphoma
Anaplastic large cell lymphoma (ALCL) makes up 10% of all childhood NHLs. It is more common in younger children.
Most anaplastic large cell lymphoma starts in T cells, although some arise from other cells. The 2 main forms of ALCL are systemic (widespread in the body) or primary cutaneous (skin only). Systemic ALCL can start in lymph nodes in the neck or other parts of the body. It may also start outside the lymph nodes, including in the skin, lungs, bone, digestive system or other organs. When it starts outside of the lymph nodes, it is described as extranodal.
Systemic ALCL is often diagnosed when it has spread to other parts of the body. Children commonly have fevers, night sweats and weight loss at diagnosis.
Rare types of childhood NHL
Rare types of childhood NHL include:
- post-transplant lymphoproliferative disease (PTLD)
- follicular NHL
- marginal zone lymphoma, which can appear as nodal or extranodal mucosa-associated lymphatic tissue (MALT) lymphoma
- primary CNS lymphoma
- peripheral T-cell lymphoma
- cutaneous T-cell lymphoma