Hodgkin lymphoma (HL) is a cancer of the lymph system and is diagnosed by the identification of a characteristic cell under the microscope (the Reed- Sternberg cell). Hodgkin lymphoma typically begins in the lymph nodes in one region of the body and then spreads through the lymph system in a predictable manner. Fortunately, if treated appropriately HL is a curable cancer for the majority of patients. More than 75% of all newly diagnosed patients can be cured with combination chemotherapy, precision cancer medicines and/or radiation therapy. (1) Mortality has fallen more rapidly than for any other cancer over the last 5 decades. (2)
About the lymphatic system
The lymphatic system is made up of lymph nodes connected by lymphatic vessels and organs throughout the body. The lymphatic system contains a type of white blood cell called a lymphocyte that is the key cell in the immune system to fight infection and lymphoma.
Other Key Organs of the Lymphatic System Include:
- Spleen: located in the left upper abdomen, under the rib cage.
- Thymus: located behind the breastbone and helps develop T-lymphocytes.
- Tonsils: located in the throat which help trap bacteria entering through the mouth
Hodgkin lymphoma most commonly affects lymph nodes in the neck or in the area between the lungs and behind the breastbone but may involve any part of the lymph system and even spread to other organs such as the lungs, liver, bone and bone marrow.
Types of Hodgkin lymphoma
There are different types of Hodgkin lymphoma. Doctors determine the type of Hodgkin lymphoma by performing a biopsy to see how the cells look under a microscope and whether the cells contain certain bio-markers.
Classical Hodgkin lymphoma (cHL) – Accounts for ~ 95% of cases of Hodgkin lymphoma and is diagnosed when characteristic abnormal lymphocytes, known as Reed-Sternberg cells are identified in the biopsy. cHL is divided into 4 subtypes:
- Nodular sclerosis Hodgkin lymphoma is the most common type of cHL It affects up to 80% of people diagnosed with cHL. It is most common in young adults, especially women and typically affects the lymph nodes in the central part of the chest, called the mediastinum.
- Lymphocyte-rich classical Hodgkin lymphoma occurs in ~ 6% of people with cHL. It is more common in men and usually affects areas other than the mediastinum.
- Mixed cellularity Hodgkin lymphoma occurs most often in older adults and most commonly develops in the abdomen.
- Lymphocyte-depleted Hodgkin lymphoma is the least common subtype of cHL. It is most common in older adults; people with the human immunodeficiency virus (HIV), and people in non-industrialized countries. Nodular lymphocyte-predominant Hodgkin lymphoma
Nodular lymphocyte-predominant Hodgkin lymphoma represents ~5% of all Hodgkin lymphomas and it often develops in the lymph nodes in the neck, groin, or armpit in younger patients. It is more similar to B cell non-Hodgkin lymphoma and has characteristic “popcorn cells” or “LP cells” that have a marker called CD20 on their surface. Nodular lymphocyte-predominant Hodgkin lymphoma is often treated differently from cHL.