Cancerwise

You may have already heard about non-Hodgkin lymphoma. But are there other kinds of lymphoma? What makes each one unique? And, are some symptoms common to all types of lymphoma?

We went to lymphoma specialist Ranjit Nair, M.D., for answers to these and other questions. Here’s what he shared. 

What is lymphoma?

Because of its name, you might assume that lymphoma is a cancer of the lymph nodes. But lymphoma is actually a cancer of lymphocytes, which are a type of white blood cell. These white blood cells originate in the bone marrow. Once they mature, they are deployed to live and work within the lymphatic system — primarily the lymph nodes, spleen and thymus. 

When a mature lymphocyte becomes cancerous, it tends to settle and multiply in the areas where it was designed to work. That’s why swollen lymph nodes are the most common symptom of lymphoma. 

The name itself actually provides a road map of the disease: “lymph” refers to the fluid and system these cells inhabit, while the suffix, “-oma,” is the medical term for a swelling or tumor.

How many different types of lymphoma are there?

Many. But generally speaking, lymphomas are classified as either Hodgkin or non-Hodgkin. They were named in honor of Thomas Hodgkin, the 19th century British physician who first described these abnormalities in 1832. For a long time, any lymphoma that didn’t fit his specific description was simply classified as “non-Hodgkin.” 

How is lymphoma broken down beyond those two categories?

Lymphoma is further categorized by the specific type of immune cell involved and its behavior. There are two main types of lymphocytes — B cells and T cells — so each cancer is classified accordingly. 

• Hodgkin lymphoma is almost exclusively a B cell malignancy. It has four different subtypes. 
• Non-Hodgkin lymphoma, however, is a mix of both B and T cell varieties. It serves as a much larger umbrella for approximately 140 different diseases. 

B cell lymphomas are the most common, while T cell lymphomas are extremely rare. Despite the many varieties, though, lymphoma remains a rare disease. It makes up only about 4% to 5% of all new cancer diagnoses annually.  

What are the most common types of lymphoma?

Lymphomas can be further described as either indolent (slow-growing) or aggressive (fast-growing). 

The most common type of aggressive lymphoma is diffuse large B cell lymphoma, which actually includes 15 to 20 different genetic varieties. The most common indolent variety is follicular lymphoma. 

Some of the rarer types include mantle cell lymphoma, marginal zone lymphoma, cutaneous T-cell lymphoma and double-hit lymphoma.