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A lymphoma is a cancer that arises from the lymphocytes
Lymphocytes are the white blood cells that are responsible for ensuring our body’s immunity and defense against external micro invaders. A lymphoma can develop anywhere lymphoid tissue is found: in the spleen, bone marrow, in the lymph nodes or other organs. Compared to leukemias, lymphomas are solid tumors of lymphocytes, whereas leukemias are not solid tumors, are affect mostly circulating lymphocytes (compared to fixed lymphocytes as in lymphomas).
Because lymphomas develop from B lymphocytes, when someone is suffering from one, he therefore experiences a myriad of symptoms referred to as “B-symptoms”: weight loss, fever, night sweats, decreased appetite, etc. And these occur in all lymphomas. However, depending on how aggressive the lymphoma is, the symptoms might progress slowly or quickly and the condition could quickly deteriorate.
How do you know which one is Hodgkin’s or Non-Hodgkin’s?
Hodgkin’s Lymphoma derives its name from Mr. Thomas Hodgkin, a graduate of the University of Edinburgh who first described the disease. A priori, all lymphomas were found to have the same characteristics (cell surface markers, symptoms, metastasis profiles, etc.). While he was working as a Museum Curator at the Guy’s Hospital, Mr. Thomas Hodgkin initiated a study on seven patients who were found to suffer from painless lymph node enlargement. Reports were made of enlargement of lymph nodes in the neck region, as well as of the spleen. Later on, cytological analysis of those lymph nodes revealed a rather interesting appearance of the cells: the cancerous cells were binucleated (two nuclei) resembling an owl’s eye. They are thought to be B cells that have not undergone hypermutation to express antibodies. These cells are called “Reed-Sternberg cells”, named after Dorothy Reed Mendenhall and Carl Sternberg who first described the definitive microscopic findings of Hodgkin lymphoma. With that said, the Reed-Sternberg cells are almost always confirmatory for the presence of Hodgkin Lymphoma, thus differentiating it from any other lymphomas. Henceforth, any other lymphoma without the presence of the Seed-Sternberg cell is a Non-Hodgkin Lymphoma (NHL).
Although the presence of the Reed-Sternberg cell is the confirmatory sign for the diagnosis of Hodgkin Lymphoma, other factors could also help us to differentiate between Hodgkin Lymphoma and Non-Hodgkin lymphoma while waiting for a confirmatory biopsy.
Causes of lymphoma
It is commonly believed that the highest risk factor to developing a lymphoma is a family history of the same. This is due to the fact that mutation in B-cells related genes are inherited along generations.
This is probably due to the fact that the EBV trigger B lymphocytes, thus causing accelerated proliferation and therefore increasing the risk of cancer.
In Hodgkin Lymphoma, the affected lymph nodes are contiguous. In other words, they follow a specific chronological pattern” starting in the shoulders, then the neck, then the chest. Non-Hodgkin lymphomas however could arise anywhere and affect any type of lymph nodes at a given time, with no specific pattern.