Is Lymphoma a Blood Cancer?

Most people are familiar with the word cancer—and many have even heard the term blood cancer. However, lymphoma might be a term less familiar to some, despite it being one of the most common blood cancers. In fact, lymphoma is the most common type of blood cancer in adults and the third most common in children.

So, is lymphoma a blood cancer? Yes. Lymphoma begins in the lymphocytes—a type of white blood cell that plays a critical role in protecting the body from infection. Understanding why lymphoma is classified as a blood cancer and how it differs from other forms of cancer is essential for patients, care partners, and advocates seeking the right information, treatment options, and support.

Why Lymphoma Is a Blood Cancer?

Blood cancers are diseases that start in the blood, bone marrow, or lymphatic system. Lymphoma fits this definition because it develops in the lymphatic system:

• Origin in White Blood Cells (Lymphocytes): Lymphoma starts when normal lymphocytes (B cells, T cells, or NK cells) grow and multiply uncontrollably.
• Circulation in the Body: Because the lymphatic system is connected to blood flow, abnormal lymphoma cells can travel throughout the body.
• Systemic Disease: Unlike solid tumors that typically begin in one organ, lymphoma affects the blood and immune system, making it a systemic (whole-body) disease from the start.

This makes lymphoma fundamentally different from solid tumor cancers and places it firmly in the category of blood cancers.

What Makes Lymphoma Different?

Lymphoma develops in the lymphatic system—a network of lymph nodes, spleen, thymus, and bone marrow that helps regulate the immune response. Unlike solid tumors that usually begin in one organ, lymphoma is systemic, meaning it can spread and grow in many parts of the body, including the lymph nodes, spleen, bone marrow, and other organs.

Here are a few key distinctions that set lymphoma apart:

• Where it starts: Lymphoma begins in B cells, T cells, or NK cells—specialized white blood cells.
• How it spreads: Because the lymphatic system is connected throughout the body, lymphoma can appear in multiple areas, not just one organ.
• How it behaves: Each of the more than 100 subtypes of lymphoma behaves differently, making accurate diagnosis critical to selecting the right treatment.

100 Distinct Subtypes

One of the defining characteristics of lymphoma is its unique heterogeneity. In fact, there are more than 100 different subtypes of lymphoma, and the list continues to grow.  Each type of lymphoma has a different biology, prognosis, clinical course, and therefore different treatment and monitoring strategies.

What is true for one type of lymphoma may be completely different for another type, making it crucial for patients to fully understand their specific lymphoma diagnosis. There are three major categories of lymphoma:

• Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (CLL/SLL): CLL/SLL are the same disease (and a type of lymphoma) with slightly different manifestations. Where the cancerous cells gather determines whether it is called CLL or SLL. Leukemic cells develop because of a change that takes place in the cell’s DNA.
• Hodgkin Lymphoma (HL): There are five types of HL, a form of lymphoma that involves the Reed-Sternberg cells.
• Non-Hodgkin Lymphoma (NHL): There are more than 90 types of NHL, some of which are more common than others. Any lymphoma that is not CLL/SLL or that does not involve Reed-Sternberg cells is classified as a non-Hodgkin lymphoma.

Each category is further subdivided into numerous types that differ in the type of cell they originated from (B, T, or NK cells), the way they develop and spread, and the way they are treated. Unlike other cancers, lymphoma therapy and prognosis (how well the patient will do) are determined by the lymphoma type, the presence of certain markers in lymphoma cells, and other factors like age and other medical issues, more than by the stage of the disease (how advanced the disease is).

The Role of the Lymphoma Research Foundation

The Lymphoma Research Foundation’s mission is to realize the promise of science to eradicate lymphoma and serve the community touched by this disease.

The Foundation is laser-focused on providing accurate information, advancing cutting-edge research, and trusted support tailored specifically for lymphoma. For patients and families navigating the complexities of this disease, that dedication matters. That is why we exist—and why our role is more critical than ever. As the nation’s only nonprofit devoted exclusively to lymphoma, the Foundation provides:

• Expert-reviewed education tailored specifically to lymphoma patients and care partners.
• Free support services providing the guidance, resources, and compassion needed to navigate this journey.
• Investment in research to support the careers of hundreds of scientists and drive discoveries that have transformed patients’ lives.

For three decades, we’ve built a community rooted in research dedicated to eradicating lymphoma. By bringing together the promise of science and the power of people, a future without lymphoma is within our reach.