Hodgkin's and non-Hodgkin's Lymphoma: What's the Difference?

Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL) are both blood cancers that develop in the lymphatic system. These cancers occur when lymphocytes-types of white blood cells in the immune system that help protect us from infection and disease—start to grow abnormally and develop into lymphomas.

The Differences
Although these diseases share similar names, they are quite different. The main difference between Hodgkin's and non-Hodgkin's lymphoma is the composition of the cells that indicate the disease. When viewed under a microscope, if a specific type of abnormal cell, called a Reed-Sternberg cell, is detected, that indicates Hodgkin's lymphoma. If a Reed-Sternberg cell is not present, that signals non-Hodgkin's lymphoma.

"Hodgkin's lymphoma is very rare; it doesn't spread via the blood system, rather it spreads lymph node to lymph node in an orderly fashion," explains Dr. Owen O'Connor, Director, Center for Lymphoid Malignancies in New York. "It is treated with a classic chemotherapy regimen, which cures about 70 percent of all cases."

Non-Hodgkin's lymphoma, on the other hand, is not a single disease, but rather a group of 65 related cancers. "It spreads via the blood and is a systemic disease from the onset, explains Dr. O'Connor. "The treatment is tailored to the specific type and aggressiveness that you have."

Although the various types of NHL have some common characteristics, they differ in how they look under the microscope, molecular features, growth patterns, impact on the body, and how they are treated. Non-Hodgkin lymphomas are divided into two major groups: B-cell and T-cell lymphomas. B-cell lymphomas develop from abnormal B-lymphocytes and account for 85 percent of all NHLs. T-cell lymphomas develop from abnormal T-lymphocytes and account for the remaining 15 percent of all NHLs. Treatment usually includes some form of chemotherapy, radiation, biologic therapy, or a combination. According to the Lymphoma Research Foundation, approximately 30 to 60 percent of patients with an aggressive form of non-Hodgkin lymphoma can be cured.

Signs and Symptoms

As these are diseases of cells that play a role in our immune systems, symptoms are not lymphoma-specific and are similar to those of other illnesses. Common symptoms include:

  • Swelling of lymph nodes, which may or may not be painless
  • Fever
  • Unexplained weight loss
  • Sweating (often at night)
  • Chills
  • Lack of energy
  • Itching

As these symptoms are common for other illnesses, most people who have these complaints will not have lymphoma. However, if you have persistent symptoms, it is important that you visit your doctor for an examination.

Who is at Risk?
According to the American Cancer Society, 9,060 new cases of HL will be diagnosed in 2012, compared to 70,130 new cases of NHL. There is a slight predominance in men for both diseases.

Though the causes remain unknown, the risk may be higher in individuals who:

  • Have a family history (though no hereditary pattern has been well established)
  • Are affected with an autoimmune disease
  • Have received an organ transplant
  • Have been exposed to chemicals such as pesticides, fertilizers, or organic solvents for a long period
  • Have been infected with viruses such as Epstein-Barr, human T-lymphotropic virus type 1 (HTLV-1), HIV/AIDS, hepatitis C, or certain bacteria, such as H-pylori

 

Sources:

Leukemia and Lymphoma Society
http
://www.lls.org/#/diseaseinformation/lymphoma

American Cancer Society
Cancer Facts & Figures 2012 (pdf)

Lymphoma Research Foundation
http
://www.lymphoma.org/