»Lymphoma«

Non-Hodgkin's lymphoma is a cancer of the lymphatic system. The lymphatic system is part of the body's immune system and helps us fight infection. It is a complex system made up of organs, such as the bone marrow, the thymus, and the spleen, and the lymph nodes (or lymph glands). These are connected by a network of tiny lymphatic vessels.

Lymph nodes are found all over the body. Lymph is a colourless liquid. It circulates through the lymphatic system. It contains cells known as lymphocytes. Lymphocytes are a type of white blood cell and are an essential part of the body's defence against infection and disease.

There are two main types of lymphocyte: B-cells and T-cells. Most lymphocytes start growing in the bone marrow. The B-cells continue to develop in the bone marrow. The T-cells go from the bone marrow to the thymus gland (behind the breast bone) and mature there. When they are mature, both B-cells and T-cells help to fight infections.

A diagram showing the main groups of lymph nodes in the body (d)

»Classification«

The Working Formulation, published in 1982, is primarily descriptive but remains the most widely used classification of non-Hodgkin lymphoma today.

• Low Grade
  • Malignant Lymphoma, small lymphocytic (chronic lymphocytic leukemia)
  • Malignant Lymphoma, follicular, predominantly small cleaved cell
  • Malignant Lymphoma, follicular, mixed (small cleaved and large cell)
• Intermediate Grade
  • Malignant Lymphoma, follicular, predominantly large cell
  • Malignant Lymphoma, diffuse, small cleaved cells
  • Malignant Lymphoma, diffuse, mixed (small and large cells)
  • Malignant Lymphoma, diffuse large cells
• High Grade
  • Malignant Lymphoma, large cell, immunoblastic
  • Malignant Lymphoma, lymphoblastic
  • Malignant Lymphoma, small non-cleaved cells (Burkitt's lymphoma)
• Miscellaneous
  • Composite
  • Mycosis fungoides
  • Histiocytic
  • Extramedullary plasmacytoma
  • Unclassifiable

The WHO Classification is the latest classification of lymphoma, published by the World Health Organization in 2001. This classification attempts to classify lymphomas by cell type, i.e. the normal cell type that most closely resembles the tumour. They are classified in three large groups: the B cell tumours, the T cell and natural killer cell tumours, Hodgkin lymphoma, and other minor groups:

• Mature B Cell Neoplasms
  • Chronic lymphocytic leukemia/small lymphocytic lymphoma
  • B-cell prolymphocytic leukaemia
  • Lymphoplasmacytic lymphoma/Waldenström macroglobulinemia
  • Splenic marginal zone lymphoma
  • Plasma cell neoplasms
    • Plasma cell myeloma
    • Plasmacytoma
    • Monoclonal immunoglobulin deposition diseases
    • Heavy chain diseases
  • Extranodal marginal zone B cell lymphoma (MALT lymphoma)
  • Nodal marginal zone B cell lymphoma
  • Follicular lymphoma
  • Mantle cell lymphoma
  • Diffuse large B cell lymphoma
  • Mediastinal (thymic) large B cell lymphoma
  • Intravascular large B cell lymphoma
  • Primary effusion lymphoma
  • Burkitt lymphoma/leukemia
  • lymphomatoid granulomatosis
• Mature T cell and Natural Killer (NK) Cell Neoplasms
  • T cell prolymphocytic leukemia
  • T cell large granular lymphocytic leukemia
  • Agressive NK cell leukemia
  • Adult T cell leukemia/lymphoma
  • Extranodal NK/T cell lymphoma, nasal type
  • Enteropathy-type T cell lymphoma
  • Hepatosplenic T cell lymphoma
  • Blastic NK cell lymphoma
  • Mycosis fungoides/Sezary syndrome
  • Primary cutaneous CD30-positive T cell lymphoproliferative disorders
    • Primary cutaneous anaplastic large cell lymphoma
    • Lymphomatoid papulosis
  • Angioimmunoblastic T cell lymphoma
  • Peripheral T cell lymphoma, unspecified
  • Anaplastic large cell lymphoma
• Hodgkin Lymphoma
  • Nodular lymphocyte-predominant Hodgkin lymphoma
  • Classical Hodgkin lymphoma
    • Nodular sclerosis
    • Mixed cellularity
    • Lymphocyte-rich
    • Lymphocyte depleted
• Immnuodeficiency-Associated Lymphoproliferative Disorders
  • Associated with a primary immune disorder
  • Associated with the Human Immunodeficiency Virus (HIV)
  • Post-transplant
  • Associated with Methotrexate therapy
• Histiocytic and Dendritic Cell Neoplasms
  • Histiocytic sarcoma
  • Langerhans cell histiocytosis
  • Langerhans cell sarcoma
  • Interdigitating dendritic cell sarcoma/tumour
  • Follicular dendritic cell sarcoma/tumour
  • Dendritic cell sarcoma, unspecified

»Research«

The Lymphatic System

(lĬmfãt´Ĭk) , network of vessels carrying lymph, or tissue-cleansing fluid, from the tissues into the veins of the circulatory system. The lymphatic system functions along with the circulatory system in absorbing nutrients from the small intestines. A large portion of digested fats are absorbed via the lymphatic capillaries. Like the blood circulatory system, the lymphatic system is composed of fine capillaries that lie adjacent to the blood vessels. These merge into larger tributaries known as trunks, and these in turn merge into two still larger vessels called ducts. The thoracic and right lymphatic ducts empty into the venous system in the region of the collarbones. Lymph, a colorless fluid whose composition is similar to that of blood except that it does not contain red blood cells or platelets, and contains considerably less protein, is continuously passing through the walls of the capillaries. It transports nutrients to the cells and collects waste products. Most of the lymph returns to the venous capillaries; however, a small amount (about 10%) enters the terminal lymphatic capillaries and is returned to the blood via the lymphatic system. The fluid that flows through the lymphatic system is functionally important because it contains substances having large molecules (such as proteins and bacteria) that cannot enter the small pores of the venous capillaries. Along the lymphatic network in certain areas of the body (neck, armpit, groin, abdomen, chest) are small reservoirs, the lymph nodes, which collect bacteria and other deleterious agents from the lymph which passes through them, and act as a barrier against the entrance of these substances into the bloodstream. In a disease state, therefore, the lymph nodes may become filled with harmful material to the degree where they can be seen or felt; therefore, enlarged lymph nodes are of diagnostic importance. Such enlargement of the lymph nodes can be a warning sign of various kinds of cancer, including breast cancer and Hodgkin's disease. In cases where a cancerous growth has developed, removal of lymph nodes may help to prevent its further spread. However, such a procedure also slows the flow of lymph and may thus render some of the body vulnerable to infection.

Lymph Nodes

The lymph nodes play an important part in the body's fight against infection. Lymph nodes act as a biological filter cleaning out microorganisms from the fluids that pass through them

Lymphatics and the Breast

All cells in the body contain fluid and are surrounded by fluid. The body has a secondary circulatory system called the lymphatic system to manage this fluid. Lymph comes from the blood stream and flows back into the lymphatic system. If you experience persistant edema (swelling), it may signal a problem with the heart or circulatory system.

Female breast tissue has an extensive lymphatic system. If a breast tumor invades this system, then the cancer can move to other parts of the body (metastasis).

»Signs & Symptoms«

(1)

The first symptom of non-Hodgkin's lymphoma is often a painless swelling of a lymph node in the neck, the groin, or under the arm. Other symptoms include fever, night sweats, itching, and unexplained weight loss. Diagnosis is made by laboratory study of tissue obtained by taking a biopsy of the suspicious lymph node or nodes.

(2)

The first sign of the condition is often a painless swelling in the neck, armpit or groin, caused by enlarged lymph nodes. Often, more than one group of nodes is affected. This lymphoma may also occur in skin and sometimes in other organs such as the lungs, liver, bone marrow or bones.

»Treatment«

(1)

Treatment depends on how far the disease has progressed. It may include external-beam radiation therapy, chemotherapy, or biological therapy (boosting the body's immune response to the disease). Rituxan, a genetically engineered drug involving monoclonal antibodies, has been approved for use against some low-grade (slow-growing) non-Hodgkin's lymphoma. 

Bone marrow transplantation is also sometimes used. In this technique, bone marrow (blood cell-producing tissue inside bone) is taken from the patient and treated to kill any cancer cells. The patient is then given very high dose chemotherapy designed to destroy the cancer; it also destroys the remaining bone marrow. After chemotherapy, the stored marrow is reinserted into the patient. In children, chemotherapy is the most common treatment.