What is it, Causes, Diagnosis, Treatment and More
Author: Nikol Natalia Armata
Editors: Alyssa Haag, Emily Miao, PharmD
Illustrator: Jillian Dunbar
Copyeditor: David Walker
What is lymphedema?
Lymphedema refers to the chronic accumulation of lymphatic fluid within soft tissues of the body that causes swelling of the affected area. It is usually identified in the extremities (i.e., arms or legs) but can be found anywhere in the body, including the face, oral cavity, neck, chest, and genitals. It is most widely identified in individuals with cancer; notably, one in five survivors of breast cancer will, later on, develop lymphedema.
The lymphatic system is part of the immune system. It consists of lymphatic vessels that collect the excess interstitial fluid (i.e. fluid consisting of proteins, white blood cells, and water) that is not reabsorbed by the capillaries and returns it to the blood. Once the interstitial fluid is contained in the lymphatic vessels, the fluid is now called lymph. The lymph enters the lymphatic system through the lymphatic capillaries that then drain into larger lymphatic trunks and nodes. This flow is accomplished by the pulse of nearby arteries, neighboring muscles’ contractions, and valves present within the lymphatic vessels.
Lymphedema can be classified as either primary or secondary, depending on the origin of the condition. Primary lymphedema is a rare, inherited condition that affects 1 in 100,000 individuals. It results from errors in lymphatic development and can present at different stages of life. On the other hand, secondary lymphedema is much more common, seen in approximately 1 out of 1,000 people. Typically, it is the result of injury or obstruction to a fully developed lymphatic system.
What causes lymphedema?
Primary lymphedema develops from genetic mutations that affect the development of the lymphatic system. It is mostly inherited as an autosomal dominant trait (i.e., it requires only one copy of the altered gene to be inherited from either parent in order for the condition to impact the offspring); however, expression may vary in each individual.
Secondary lymphedema, on the other hand, results from damage or obstruction of a previously functional lymphatic system. The most common cause of lymphedema worldwide is lymphatic filariasis, a parasitic infection typically caused by the Wuchereria bancrofti roundworm. Secondary lymphedema can also occur when the flow of lymph fluid is blocked by cancerous cells, compressed externally by a tumor or fatty tissue (e.g., obesity), or damaged following radiation therapy. It is also very frequently seen in individuals who have undergone treatment for breast cancer as a direct consequence of the removal of lymph nodes.
What are the signs and symptoms of lymphedema?
Signs and symptoms of lymphedema may vary depending on the severity of the lymphedema. In the early stages, lymphedema presents as a swelling in the affected area. As the lymphedema progresses, the skin may begin to feel tender and may slowly change in color and texture. The skin may also feel firm to touch and appear scaly. The affected area may also be painful with altered sensation. Sometimes, fitting into clothing can be more difficult due to restricted movement of the joints and excessive swelling. In more severe cases, small bumps and blisters filled with lymph may appear on the skin.
A very characteristic sign of lymphedema is that, when pressure is applied to the skin, no indentation forms in the affected area (i.e., non-pitting edema). Notably, attempting to but being unable to pinch and lift the skin on the top of the hand or foot, depending on where the edema is located (i.e., Stemmer's sign), is indicative of lymphedema.
How do you diagnose lymphedema?
Lymphedema is generally identified through an individual’s detailed medical history and physical examination. The identification of risk factors, like past infections, foreign travels, history of cancer, and previous surgeries that included lymph node dissection, can be helpful when trying to diagnose lymphedema. Other risk factors may include older age, obesity, and autoimmune diseases. When suspecting lymphedema, a Stemmer sign is typically assessed. If the skin cannot be pinched, the sign is positive, thereby indicating lymphedema. If the skin can be pinched, the sign is negative, suggesting the likelihood of another type of edema.
Imaging tests, such as ultrasound; CT; and especially MRI, which has a great sensitivity in investigating soft tissues, can all help identify masses that might be the underlying cause of the lymphatic compression. Additional diagnostic methods can include a specific type of radioactive imaging called lymphoscintigraphy, which is an imaging test that shows the movement of fluids in the lymphatic system. Through an injected protein dye that can detect unusual occurrences causing the edema, lymphoscintigraphy is primarily used in cancer diagnosis to identify the initial lymph nodes associated with cancer (i.e., sentinel lymph nodes).
How do you treat lymphedema?
Lymphedema is a chronic but progressive condition; therefore, beginning treatment from an early stage is very important. Most mild cases of lymphedema can resolve with skincare, which hydrates and soothes the tightened skin, and exercise, which activates the muscles and enhances lymphatic flow. Combined with the aforementioned treatment options, elevation of the affected limb can enhance the circulation of lymph. Compression bandages and garments may also be recommended in cases of mild lymphedema. In more severe cases, treatment can involve decongestive physiotherapy, such as lymphatic massage, multilayer bandaging, or wearing compression garments.
When the conservative treatment options are no longer effective, surgery is typically suggested. Liposuction is very successful in reducing the volume of lymph in the affected area. Other, minimally invasive techniques, like microsurgical lymphaticovenous anastomosis, are also promising as they allow natural drainage of the excessive lymphatic fluids through the venous system. Lastly, Suction-Assisted Protein Lipectomy is the most effective in severe cases and includes direct excision of lymphatic and fatty deposits that have not regressed with the previous techniques.
How do you treat lymphedema in the legs?
Treating lymphedema in the leg follows the exact same principles as the aforementioned treatments. Skincare, exercises focused on strengthening the lower limb, and the use of compression socks is suggested for lymphedemas that can be managed conservatively. But in more severe cases, reconstruction of the lymphatic and venous vessels of the affected leg in addition to removal of excess lymph and fat can be life-saving. Lymphedema therapists, healthcare professionals specialized in treating lymphedema, can provide individuals with a treatment plan based on their needs.
What are the most important facts to know about lymphedema?
Lymphedema occurs when excess lymphatic fluid builds up in the body, causing non-pitting swelling. It usually occurs in the limbs and results from either genetic mutations that affect the development of the lymphatic system (primary lymphedema) or underlying medical conditions that cause damage or obstruction to the lymphatic system. Diagnosis of lymphedema involves thorough medical history review, physical examination, and imaging tests to confirm the diagnosis. Treatment begins with techniques that enhance the lymph flow, like exercise, massage, and compression garments, but can proceed to more invasive methods for more severe or refractory cases.
Watch related videos:
Lymphatic system anatomy and physiology
Breast cancer: Pathology review
Wuchereria bancrofti (Lymphatic filariasis)
Resources for research and reference
Grada, A. A., & Phillips, T. J. (2017). Lymphedema: Pathophysiology and clinical manifestations. Journal of the American Academy of Dermatology, 77(6), 1009–1020. DOI: 10.1016/j.jaad.2017.03.022
Kayıran, O., De La Cruz, C., Tane, K., & Soran, A. (2017). Lymphedema: From diagnosis to treatment. Turkish journal of surgery, 33(2), 51–57. DOI: 10.5152/turkjsurg.2017.3870
Sleigh BC, Manna B. Lymphedema. (Updated 2021 Jun 4). In: StatPearls [Internet]. Retrieved from: https://www.ncbi.nlm.nih.gov/books/NBK537239/