Recent data from the Leukemia and Lymphoma Society report that there are currently over 628,000 people in the United States living with some form of lymphoma. This includes over 474,000 diagnoses of non-Hodgkin lymphoma, and over 153,000 diagnoses of Hodgkin lymphoma (HL).
Hodgkin lymphoma is distinguished from other diseases classified as lymphoma primarily because of the presence of Reed-Sternberg cells, which are large, cancerous cells found in Hodgkin lymphoma tissues. Non-Hodgkin lymphomas (NHL) represent a varied group of diseases distinguished by the features of the cancerous cells with each disease type.
Non-Hodgkin lymphomas can originate in the B-cells (ex. Burkitt lymphoma, chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), diffuse large B-cell lymphoma, follicular lymphoma, immunoblastic large cell lymphoma, precursor B-lymphoblastic lymphoma, and mantle cell lymphoma) or T-cells ( mycosis fungoides, anaplastic large cell lymphoma, and precursor T-lymphoblastic lymphoma). They can affect multiple parts of the the lymphoid tissue, including the lymph nodes, spleen, and the bone marrow and are further classified into fast-growing or slow-growing. There have been over sixty different subtypes of NHL identified, and 6 subtypes of HL, and those numbers are increasing.
Generally, the symptoms of NHL and HL are non-specific, most commonly including shortness of breath (from lymphoma affecting the thymus or nodes around the chest), abdominal pain and swelling which can cause loss of appetite, nausea and vomiting, fatigue, fever, lymphadenopathy (swelling of the lymph nodes), drenching night sweats, intense itching of the body for unknown reason, enlargement of the spleen, and weight loss. Lymphoma in the brain can cause headaches, problems with concentration, seizures and personality changes.
The causes of most lymphomas are unknown. Most are likely caused by genetic mutations. Environmental exposure to some pesticides, chemicals and herbicides have been implicated as well. People who have autoimmune diseases, organ transplants and weakened immune systems (such as AIDS) are also at greater risk. Some viruses have been identified as causative as well, although these are regionally specific (Burkitt's lymphoma and the Epstein-Barr virus in Africa; HTLV-1 virus in Japan, southeastern US).
The cornerstone of diagnosis is pathological examination of lymphatic tissue under a microscope. A biopsy of an enlarged lymph node or bone marrow will be taken and examined to figure out the specific type of cancer based on several tissue biological markers as well as cell structure. Additionally, blood tests, CT scans of the body, and PET scans may be done to see if the cancer has metastasized.
Treatment is dependent on many factors, most importantly the type of lymphoma diagnosed, followed by the stage of the cancer, the patient's age and health status, and how symptoms have affected the body. Typically treatment involves a wide variety of chemotherapeutic agents given in specific doses and combinations for the specific lymphoma. Radiation is frequently used as well, and is usually the primary treatment for non-Hodgkin lymphoma. Additionally, many new treatments called monoclonal antibodies have been successfully used (rituximab (Rituxan) for B-cell lymphomas, ofatumumab (Arzerra) for NHL, Ocrelizumab is in trials). Some patients may benefit from a bone marrow transplant.
Prognosis for the various types of lymphoma vary depending on type and stage of advancement. While each type of lymphoma has its own prognosis, it is generally a very treatable illness, with over 80% of patients diagnosed early being alive after five years. Low-grade NHL usually progresses slowly, and sometimes it takes years for the disease to progress or even need treatment. Many types of high grade disease can be completely cured with chemotherapy. Unfortunately, if chemotherapy doesn't work, the disease can spread quickly.