Lymphoma is cancer that affects the lymphocytes, a type of white blood cells that are an integral part of the immune system for fighting immunogens and preventing bacterial or viral infections. The lymphatic system, where these cells are mostly found, is a collection of lymph nodes that carry the lymph fluid throughout the body. These cancer cells travel through the lymph nodes, so it can metastasize to all parts of the body.

The different types of lymphoma
Based on the cells that are affected, lymphomas are classified into the following types:

Chronic lymphocytic leukemia/small lymphocytic lymphoma
This is a form of cancer that affects the lymphocytes and leads to the formation of leukemic cells due to a change that occurs in the DNA of the cells. Both these conditions are essentially the same disease, but they are differentiated based on where the cancerous cells manifest in majority.

• Chronic Lymphocytic Leukemia (CLL)
  When the cancerous cells are mostly present in the bone marrow and the blood, it is referred to as CLL.
• Small Lymphocytic Lymphoma (SLL)
  When the cells displaying cancerous growth are located majorly in the lymph nodes, it is called SLL.

Hodgkin lymphoma
Usually affecting the lymph nodes, Hodgkin lymphomas are observed when cancer leads to the development of large, abnormal lymphocytes called Reed-Sternberg cells. The disease can metastasize throughout the body as the cancerous cells travel from one lymph node to another. Hodgkin lymphomas are broadly classified into classical Hodgkin lymphomas and nodular lymphocyte-predominant Hodgkin lymphomas (NLPHL). The former type is diagnosed in about 95 percent of all Hodgkin lymphoma cases, and it can be further subdivided into the following categories:

• Nodular sclerosis
• Mixed cellularity
• Lymphocyte-rich
• Lymphocyte-depleted

Non-Hodgkin lymphoma
All lymphomas that are not Hodgkin lymphomas are called non-Hodgkin lymphomas. When the cancerous growths do not lead to the development of Reed-Sternberg cells, it is a case of Non-Hodgkin lymphomas. This is categorized into over 30 different types of lymphoma depending on the type of lymphocytes affected, but the broad classification is into the following two types:

• B-cell lymphomas
  The cancerous growth begins in the B-cells, and these lymphomas are further classified into diffuse large B-cell lymphomas, follicular lymphomas, mantle cell lymphomas, marginal zone lymphoma. B-cell lymphomas account for 90 percent of all cases of non-Hodgkin lymphomas.
• T-cell lymphomas
  Here, cancer develops in the killer T-cells of the body, and this type is diagnosed in 10 percent of all patients with non-Hodgkin lymphomas.

Lymphoma is majorly caused by genetic changes in the DNA of the lymphocytes and can be effectively treated if detected in the early stages. The different types of lymphoma can be treated using a variety of methods based on the doctor’s recommendation. These treatment options include chemotherapy, radiotherapy, immunotherapy, and stem cell transplant.