5 Major Differences Between Leukemia and Lymphoma

Leukemia versus lymphoma: what is the difference?.

1. Different Definitions

Leukemia and lymphoma are defined in a way that may seem odd, with a lot of exceptions and overlapping concepts. This is in part because these definitions were developed long ago, starting in the 1800s. To better understand the differences, one key item to pay attention to is whether or not the malignancy is typically associated with high numbers of white blood cells, or leukocytes, circulating out in the peripheral circulation, or the bloodstream.

This is more typical of leukemia. Another key consideration is early involvement of the bone marrow, which is also more typical of leukemia.

Lymphoma is defined as “any malignancy of the lymphoid tissue.”  

So, what’s the lymphoid tissue, you ask?

  • The lymphoid tissue includes both cells and organs. Cells – including some white blood cells -- and organs -- including the thymus, bone marrow, lymph nodes and spleen. The most common cell type in the lymphoid tissue is the lymphocyte. In addition to organs, lymphoid tissue also includes collections of cells located throughout the body, at strategic sites to fight off invaders. Examples of these sites include the tonsils, areas in respiratory tract, beneath moist mucous membranes, such as those of the gastrointestinal tract, and other tissues of the body.

Leukemia is defined as “a progressive, malignant disease of the blood-forming organs, characterized by distorted proliferation and development of leukocytes and their precursors in the blood and bone marrow.”

So, what are the blood-forming organs, you ask?

  • In adults, the bone marrow produces all of the red blood cells, most of the white cells called granulocytes. While lymphocyte development starts in the bone marrow, they migrate to the lymphoid tissues, and especially the thymus, the spleen, and the lymph nodes, and these tissues play a vital role in the development and maturation of the lymphocytes. Special tissues of the spleen, liver, lymph nodes, and other organs are likewise important in the maturation of monocytes.

    NOTE: If it seems to you that the definitions of leukemia and lymphoma are potentially overlapping, you are correct! See number 3, below, for more.

    2. Differing Symptoms

    Leukemia and lymphoma are not diagnosed based on symptoms alone; many symptoms overlap, or are not specific to either disease, while some other symptoms may be more characteristic of one disease or the other. Symptoms of lymphoma vary and may include painless swelling of lymph nodes in your neck, armpits or groin. Other symptoms may include persistent fatigue, fever, and chills, night sweats or unexplained weight loss. The most common types of leukemia can produce symptoms such as bone and joint pain, fatigue, weakness, pale skin, easy bleeding or bruising, fever, weight loss, and other symptoms, including swollen lymph nodes, spleen, and liver.

    3. Differing Cell Types of Origin and Cells in the Circulation

    Here are the 4 basic types of leukemia:

    1. Acute myeloid leukemia, or AML

    2. Chronic myeloid leukemia, or CML

    As these names suggest, the first two are “myeloid,” which means “of or like the bone marrow,” and also refers to the group of cells that differentiate, or grow up, from one common ancestor -- a myeloid progenitor cell.

    Also recall from the explanation of blood-forming organs, above, that the bone marrow makes the white blood cells.

    However, now look at the second two leukemia types:

    3. Acute lymphocytic leukemia, or ALL

    4. Chronic lymphocytic leukemia, or CLL

    Now, with ALL and CLL, it may seem like we are in bit of trouble with our definitions…

    The second two kinds of leukemia derive from... lymphocyte lineage.

    Technically, ALL and CLL should be lymphomas, then, right? -- since they are lymphocytic -- and lymphocytes are a cell type that is a part of lymphoid tissue. Well, not quite. Though the lymphocytes are key cells in lymphoid tissue, they start out in the bone marrow and migrate to the lymphoid tissue.

    Additionally, it’s now time to go back to that nagging clause in the definition of leukemia:

    “…characterized by distorted proliferation and development of leukocytes and their precursors in the blood and bone marrow.”

    The proliferation, or growth and multiplication, of white blood cells and their precursors in the bone marrow -- and presence in the bood -- is a part of the leukemia definition that serves to distinguish many leukemias from many lymphomas.

    Here are the 2 basic types of lymphoma:

    1. Hodgkin’s lymphoma, or HL

    2. Non-Hodgkin’s lymphoma, or NHL

    A huge variety of cancers derive from lymphocytes or their precursors -- these lymphoma cells will usually not appear in the peripheral blood, which means that they can’t be properly called leukemias. **There are exceptions. Also, some malignancies have features characteristic of both leukemia and lymphoma.**

    4. Overall, More People Develop Lymphoma

    Here are the American Cancer Society’s estimates for new cases in 2015:

    Lymphoma - 80,900 people

    • 71,850 non-Hodgkin’s lymphoma
    • 9,050 Hodgkin’s lymphoma

    Leukemia - 54,270 people

    • 20,830 acute myeloid leukemia
    • 6,660 chronic myeloid leukemia
    • 6,250 acute lymphocytic leukemia
    • 14,620 chronic lymphocytic leukemia
    • 5,910 other leukemia

    5. Leukemia is the Most Common Childhood Cancer

    Leukemia is the most common childhood cancer, accounting for about one-third of all cancers in children. By comparison, lymphomas are only about 10 percent of the pie.

    The second most common group of childhood cancers is malignancies of the central nervous system, including brain tumors.


    Dorland's Illustrated Medical Dictionary. Dorland. Elsevier Health Sciences, 2011.

    American Cancer Society. Cancer Facts and Figures, 2015.

    American Cancer Society. Cancer in Children

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