What structures that involved lymphedema?

The main symptom is persistent (chronic) swelling, usually of the arm or leg. Lymphedema results from lymphatic insufficiency and inadequate lymph transport. Decreased lymph transport causes an accumulation of protein-rich interstitial fluid, leading to distention, proliferation of fatty tissue and progressive fibrosis. Thickening of skin and hair loss may subsequently occur. Progressive lymphedema without adequate management can lead to functional impairment, compromised quality of life and physical deformity. Clinically, lymphedema is noted as swelling of the involved extremity. The head, neck, breast, or genitalia may also be affected.

 

Left upper extremity lymphedema in a patient treated for breast cancer with modified radical mastectomy and axillary radiation treatment.

            Multiple staging systems exist regarding lymphedema of the upper extremity. The International Society of Lymphology describes three stages of lymphedema. The staging is as follows: stage 0, latent condition with no evident swelling but impaired lymph transport; stage 1, early accumulation of fluid that subsides with limb elevation; stage 2, limb elevation alone does not reduce swelling and pitting may or may not be present; and stage 3, lymphostatic elephantiasis. These stages only refer to the physical condition of the extremity; a more detailed staging system needs to be developed to include pathology.

The lymph system is a network of lymph vessels, tissues, and organs that carry lymph throughout the body.

The parts of the lymph system that play a direct part in lymphedema include the following:

• Lymph: A clear fluid that contains lymphocytes (white blood cells) that fight infection and the growth of tumors. Lymph also contains plasma, the watery part of the blood that carries the blood cells.
• Lymph vessels: A network of thin tubes that helps lymph flow through the body and returns it to the bloodstream.
• Lymph nodes: Small, bean-shaped structures that filter lymph and store white blood cells that help fight infection and disease. Lymph nodes are located along the network of lymph vessels found throughout the body. Clusters of lymph nodes are found in the underarm, pelvis, neck, abdomen, and groin.

The spleen, thymus, tonsils, and bone marrow are also part of the lymph system but do not play a direct part in lymphedema.

Lymphedema occurs when lymph is not able to flow through the body the way that it should.

When the lymph system is working as it should, lymph flows through the body and is returned to the bloodstream.

• Fluid and plasma leak out of the capillaries (smallest blood vessels) and flow around body tissues so the cells can take up nutrients and oxygen.
• Some of this fluid goes back into the bloodstream. The rest of the fluid enters the lymph system through tiny lymph vessels. These lymph vessels pick up the lymph and move it toward the heart. The lymph is slowly moved through larger and larger lymph vessels and passes through lymph nodes where waste is filtered from the lymph.
• The lymph keeps moving through the lymph system and collects near the neck, then flows into one of two large ducts:
• The right lymph duct collects lymph from the right arm and the right side of the head and chest.
• The left lymph duct collects lymph from both legs, the left arm, and the left side of the head and chest.
• These large ducts empty into veins under the collarbones, which carry the lymph to the heart, where it is returned to the bloodstream.

When part of the lymph system is damaged or blocked, fluid cannot drain from nearby body tissues. Fluid builds up in the tissues and causes swelling.

Refferences:

1. The International Society of Lymphology: The diagnosis and treatment of peripheral lymphedema. 2009 consensus document of the International Society of Lymphology. Lymphology 2009, 42:51-60.
2. Campisi C, Boccardo F: Microsurgical techniques for lymphedema treatment: derivative lymphatic-venous microsurgery. World J Surg 2004, 28:609-613. 
3. International Society of Lymphology: The diagnosis and treatment of peripheral lymphedema: 2013 Consensus Document of the International Society of Lymphology. Lymphology 2013 Mar, 46(1):1-11. 
4. National Cancer Institute: PDQ® Lymphedema. Bethesda, MD: National Cancer Institute. Date last modified <MM/DD/YYYY>. Available at:http://cancer.gov/cancertopics/pdq/supportivecare/lymphedema/Patient. Accessed <MM/DD/YYYY>.