Blood cancer is not one single disease. It is a broad term used for cancers that begin in blood-forming tissues, such as the bone marrow, or in cells of the immune system. The three major groups are leukemia, lymphoma and myeloma, but each group contains several different subtypes.
These cancers can differ considerably in the cells they affect, how quickly they develop, where they occur in the body, and how they are treated. Identifying the exact type and subtype is therefore an important first step in planning appropriate blood cancer treatment. Here is a closer look at the major types of blood cancer and what makes them different.
What Are the Main Types of Blood Cancer?
Most discussions about blood cancer focus on three major groups:
- Leukemia – cancers that develop in blood-forming tissues, particularly the bone marrow, and affect abnormal blood-cell production.
- Lymphoma – cancers that begin in lymphocytes, a type of white blood cell involved in the immune system.
- Myeloma – cancers that develop from plasma cells, which are specialized white blood cells that normally produce antibodies.
Although these diseases are grouped together as blood cancers, they are biologically different. Even within the same group, two subtypes can behave very differently and require different treatment approaches.
1. Leukemia
Leukemia is a cancer of the blood-forming tissues. It usually begins in the bone marrow, where blood cells are produced. The abnormal cells can interfere with the production and function of healthy blood cells. Leukemia is generally classified according to two important features: the type of blood-forming cell involved and how quickly the disease develops.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
Acute vs chronic leukemia
Acute leukemia generally progresses quickly and involves immature blood-forming cells. It usually requires prompt medical evaluation and treatment.
Chronic leukemia generally develops more slowly and involves more mature abnormal blood cells. Some chronic leukemias may initially be discovered during routine blood testing before significant symptoms appear.
The major types of leukemia
Acute lymphoblastic leukemia (ALL)
ALL develops from abnormal lymphoid cells and can progress rapidly. It occurs in both children and adults, although it is particularly common among childhood leukemias.
Acute myeloid leukemia (AML)
AML develops from abnormal myeloid cells, which normally give rise to several types of blood cells. It is an acute leukemia and can progress quickly.
Chronic lymphocytic leukemia (CLL)
CLL is a usually slow-growing leukemia involving abnormal lymphocytes. It is primarily diagnosed in adults and may sometimes be found incidentally during a routine blood test.
Chronic myeloid leukemia (CML)
CML is a chronic leukemia involving abnormal myeloid cells. It generally develops more slowly than acute leukemias, particularly during its initial phase.
There are also less common forms, such as hairy cell leukemia and other rare leukemia subtypes. The precise classification may depend on laboratory, chromosome, and molecular findings in addition to the appearance of the abnormal cells.
2. Lymphoma
Lymphoma begins in lymphocytes, which are white blood cells that form part of the immune system. Lymphocytes are found in lymph nodes and other lymphatic tissues throughout the body, including the spleen and bone marrow. Lymphoma is broadly divided into two main categories:
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
- Hodgkin lymphoma
- Non-Hodgkin lymphoma
Hodgkin lymphoma
Hodgkin lymphoma is characterized by particular abnormal lymphocytes, traditionally identified as Reed-Sternberg cells in classic Hodgkin lymphoma.
Hodgkin lymphoma includes different subtypes. Most cases are classified as classic Hodgkin lymphoma, while nodular lymphocyte-predominant Hodgkin lymphoma is a less common form. The subtype, stage, and other characteristics of the disease help determine the appropriate treatment approach.
Non-Hodgkin lymphoma
Non-Hodgkin lymphoma is not one specific cancer. It includes a large group of lymphomas that can develop from B cells, T cells, or other lymphocytes.
These lymphomas can also behave very differently. Some are indolent, meaning they tend to grow slowly, while others are aggressive and can progress rapidly. Examples of non-Hodgkin lymphoma include:
- Diffuse large B-cell lymphoma
- Follicular lymphoma
- Mantle cell lymphoma
- Burkitt lymphoma
- Marginal zone lymphoma
- Several types of T-cell lymphoma
Because non-Hodgkin lymphoma includes many distinct diseases, simply knowing that a person has “lymphoma” is not enough to determine the treatment plan. The exact subtype and its biological characteristics are important.
3. Myeloma
Myeloma develops from plasma cells. Plasma cells are specialized B cells that normally produce antibodies to help the body fight infections.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
When abnormal plasma cells multiply, they can accumulate in the bone marrow and interfere with the production of healthy blood cells. They may also produce an abnormal protein called monoclonal protein or M protein.
Multiple myeloma
Multiple myeloma is the main cancer within the plasma-cell group. Abnormal plasma cells build up in the bone marrow and may form tumors in multiple bones.
The disease can affect different parts of the body and may be associated with problems such as bone damage, anemia, kidney problems, or increased calcium levels. However, not everyone experiences the same symptoms or complications.
Plasmacytoma
Plasmacytoma occurs when abnormal plasma cells form a localized tumor. It may develop in a bone or in soft tissue outside the bone marrow.
A solitary plasmacytoma is different from multiple myeloma because the abnormal plasma-cell growth is localized rather than involving multiple areas of the body.
What about MGUS?
Monoclonal gammopathy of undetermined significance (MGUS) is another plasma-cell disorder. Importantly, MGUS is not cancer. It involves an abnormal monoclonal protein and a small population of abnormal plasma cells, but without the features required for a diagnosis of multiple myeloma or another plasma-cell cancer.
MGUS can, however, progress to a blood cancer or another related disorder in some people, which is why monitoring may be recommended.
How Are Leukemia, Lymphoma and Myeloma Different?
| Blood cancer | Cell or tissue involved | Examples |
|---|---|---|
| Leukemia | Blood-forming cells, usually in the bone marrow | ALL, AML, CLL, CML |
| Lymphoma | Lymphocytes and lymphatic tissues | Hodgkin lymphoma, non-Hodgkin lymphoma |
| Myeloma | Plasma cells | Multiple myeloma, plasmacytoma |
The distinction is important because the same symptoms can sometimes occur across different blood cancers, while the underlying disease can be completely different.
Are There Other Blood Cancers?
Yes. Leukemia, lymphoma, and myeloma are the major groups commonly discussed under blood cancer, but the broader category of hematologic cancers and blood-related malignancies also includes other diseases.
These include certain myelodysplastic syndromes (MDS) and myeloproliferative neoplasms (MPNs), which affect the production and development of blood cells in the bone marrow.
There are also rare blood and immune-system cancers that do not fit neatly into the three broad categories familiar to most patients. Modern classification relies on detailed examination of the abnormal cells and their genetic and molecular characteristics.
How Do Doctors Identify the Exact Type of Blood Cancer?
A diagnosis usually requires more than a single blood test. The investigations depend on the suspected disease and may include:
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
- Complete blood count (CBC): Measures red blood cells, white blood cells, and platelets.
- Peripheral blood smear: Allows blood cells to be examined under a microscope.
- Bone marrow examination: Evaluates the cells being produced in the bone marrow and can help identify abnormal cells.
- Lymph node or tissue biopsy: Particularly important when lymphoma is suspected.
- Flow cytometry: Identifies specific markers on abnormal cells and can help determine their origin.
- Cytogenetic testing: Looks for changes in chromosomes that may help classify the disease.
- Molecular and genetic testing: Identifies specific gene or molecular changes that can influence diagnosis, risk assessment, and treatment decisions.
- Imaging tests: May be used to assess lymph nodes, organs, bones, or other areas affected by the disease.
The combination of these results allows specialists to determine the exact type and subtype of blood cancer and, when applicable, its stage or disease phase.
The Bottom Line
Blood cancer is an umbrella term covering several different diseases rather than one diagnosis. The three major groups are leukemia, lymphoma, and myeloma. Leukemia primarily involves abnormal blood-forming cells, lymphoma develops from lymphocytes, and myeloma arises from plasma cells.
Each group contains distinct subtypes, and those subtypes can behave very differently. Some develop rapidly, while others may progress slowly. Some primarily affect the bone marrow, while others may involve lymph nodes, bones, or other organs.
For this reason, identifying the exact type and subtype is essential. A detailed diagnosis provides the foundation for understanding the disease and determining which treatment approach may be appropriate.
