Cancers of the lymphatic system are termed Lymphomas. The lymphatic system is a network of vessels and nodes around the body that drain fluid (called lymph) from tissues and empty it back in to the bloodstream. Lymphoma is a broad term that covers over 50 different sub-types of disease which range from very low-grade, slow growing cancers, through to very high-grade or aggressive cancers
Lymphoma causes large numbers of abnormal lymph cells (lymphocytes) to be made. Production of normal lymphocytes can be impaired as a result, increasing the risk of infection and immune problems. The lymph nodes (often called ‘glands’) can become enlarged as they fill with these abnormal cells.
Broadly speaking, lymphoma is divided into two main types Non-Hodgkin Lymphoma (NHL) and Hodgkin Lymphoma (HL). The main difference is that Hodgkin lymphoma has an abnormal cell called a Reed-Sternberg cell and tends to occur more frequently in younger adults, although it can occasionally occur in the elderly. These two types of lymphoma behave in different ways, spread in different patterns in the body and respond to different types of treatment.
Non-Hodgkin Lymphoma is a very large group of diseases, with widely varying behavior and treatment. “Indolent” or “Low Grade” lymphomas grow slowly; the most common type is Follicular Lymphoma. Aggressive lymphomas encompass “Intermediate Grade” and “High Grade” lymphomas. These diseases grow quickly; the most common type is Diffuse Large Cell Lymphoma. Part of the initial testing in lymphoma is to determine which type of lymphoma is present, so that the optimal treatment plan can be developed.