Types of Lymphoma
There are over 60 different subtypes of lymphoma and these are divided into two main categories: Hodgkin Lymphoma (HL) and Non-Hodgkin Lymphoma (NHL). The difference between Hodgkin Lymphoma and Non-Hodgkin Lymphoma is the presence of Reed-Sternberg cells. A Reed-Sternberg cell is a cell derived from a B-lymphocyte and is only present in Hodgkin Lymphoma. If Reed-Sternberg cells are present when the tumour is examined under a microscope, the diagnosis is Hodgkin Lymphoma. If there are no Reed-Sternberg cells in a lymphatic tumour, the diagnosis is most likely to be one of the subtypes from Non-Hodgkin Lymphoma.
Of all diagnosed lymphoma cases, 90% of them are Non-Hodgkin Lymphoma and 10% Hodgkin Lymphoma. Distinguishing between Non-Hodgkin Lymphoma and Hodgkin Lymphoma is important to show different patterns of spread and to determine different treatment options.
Non - Hodgkin Lymphoma Overview
What is Non-Hodgkin Lymphoma (NHL)?
Non-Hodgkin lymphoma (NHL) is a group of blood cancers that includes all types of lymphoma except Hodgkin Lymphomas. All NHL’s are classified into two groups called B Cell Lymphomas or T Cell Lymphomas. Lymphomas arise when developing B and T lymphocytes undergo a cancerous change, and multiply in an uncontrolled way. These abnormal lymphocytes, called lymphoma cells, form collections of cancer cells called tumours, in lymph nodes and other parts of the body. The majority of lymphomas (around 85%) arise in developing B-lymphocytes (B-cell lymphomas). The remainder arise in developing T-lymphocytes (T-cell lymphomas). Within NHL there are over 60 specific types of lymphoma.
How common is NHL?
In the past 20 years, the number of people diagnosed with NHL has doubled. In Australia, there are now over 6000 people diagnosed with NHL each year. Lymphoma therefore represents the ﬁfth most common cancer diagnosed in the Australian population.
How does NHL develop?
NHL can begin in any lymph node or lymph tissue found in the body. Tumours may involve just one lymph node or several lymph nodes at the same time. Since lymphocytes move throughout the body through either the bloodstream or more commonly the lymphatic system, any abnormal lymphocyte has a clear path to travel all through the body. This is why NHL can start in or spread to any part of the body. It is for this reason that many people have widespread disease at the time of diagnosis.
What are the subtypes of NHL?
There are over 60 subtypes of lymphoma and they are categorised under B Cell Lymphomas and T Cell Lymphoma below is a list of the main subtypes.
• Diffuse Large B Cell lymphoma (DLBCL)
• Follicular Lymphoma (FL)
• Mantle Cell Lymphoma (MCL)
• Burkitt’s Lymphoma (BL)
• Chronic Lymphocytic Leukeamia (CLL)/Small Lymphocytic Lymphoma (SLL)
• Marginal Zone Lymphoma (MZL)
• Waldenstroms Macrogloulineamia (WM)
• B Cell Acute Leukaemia/Lymphoma (B-ALL)
• Cutaneous T Cell Lymphoma (CTCL)
• Adult T Cell Lymphoma/Leukaemia
• Anaplastic T Cell Lymphoma (ATCL)
• Peripheral T Cell Lymphoma (PTCL)
• T Cell Acute Leukaemia/Lymphoma (T-ALL)
HODGKIN LYMPHOMA OVERVIEW
What is Hodgkin Lymphoma?
Hodgkin Lymphoma was first identified in the 1830s by the English doctor Thomas Hodgkin. Two scientists called Reed and Sternberg studied tissue samples of people with Hodgkin Lymphoma and found a particular type of cell was always present. This cell is now called the Reed-Sternberg cell and it is larger in size than other lymphocytes. It is the presence of this Reed-Sternberg cell that distinguishes Hodgkin Lymphoma from other types of lymphoma.
Currently, it is not known how Hodgkin Lymphoma develops and research continues to investigate the cause of the disease. However, it is thought that the cancer cells grow due to an abnormal immune response from a past infection e.g. the Epstein Barr Virus (EBV) which causes glandular fever. Other people who develop Hodgkin Lymphoma may have a genetic tendency to abnormal immune responses.
What is known is that Hodgkin Lymphoma is not contagious so you cannot “catch it” from someone nor can you give it to someone else. There is no evidence to suggest that anything you have done or not done (such as lifestyle choices) will cause the development of Hodgkin Lymphoma.
How common is Hodgkin Lymphoma?
In Australia, over 600 people are diagnosed with Hodgkin Lymphoma each year. It is a rare disease, accounting for 0.5% of all cancer types diagnosed. Hodgkin Lymphoma can occur in various age groups. In developed countries, it is most likely to occur:
• Between the ages of 15 – 25 years old, or after the age of 65 years old
• In young adults, it occurs in similar numbers of males and females
• In older adults, it is more likely to occur in males
How is it treated?
Hodgkin Lymphoma is treated by a specialist doctor called a Haematologist and a Radiation Oncologist may also be involved. There are a number of things for the doctor to consider when deciding on the best treatment for a patient. These include:
1. The stage of the disease and the size of the lymph nodes
2. Age and general health/ﬁtness
3. Blood test results
4. Presence of B symptoms
Sometimes patients with the same stage of Hodgkin Lymphoma will have different treatments because of the differences in their general health and/or symptoms so do not be concerned if patients you talk to at your hospital are having different treatments. Always ask your doctor questions you may have about your lymphoma treatments and managing side effects.