Lymphedema, also known as lymphoedema and lymphatic edema, is a condition of localized fluid retention and tissue swelling caused by a compromised lymphatic system. The lymphatic system functions as a critical portion of the body's immune system and returns interstitial fluid to the bloodstream. Lymphedema is most frequently a complication of cancer treatment or parasitic infections, but it can also be seen in a number of genetic disorders. Though incurable and progressive, a number of treatments can ameliorate symptoms. Tissues with lymphedema are at high risk of infection because the lymphatic system has been compromised.
The lymphatic system is part of the vascular system and an important part of the immune system, comprising a large network of lymphatic vessels that carry a clear fluid called lymph directionally towards the heart. The lymphatic system was first described in the seventeenth century independently by Olaus Rudbeck and Thomas Bartholin. Unlike the circulatory system, the lymphatic system is not a closed system. The human circulatory system processes an average of 20 litres of blood per day through capillary filtration, which removes plasma while leaving the blood cells. Roughly 17 litres of the filtered plasma is reabsorbed directly into the blood vessels, while the remaining three litres remain in the interstitial fluid. One of the main functions of the lymph system is to provide an accessory return route to the blood for the surplus three litres.
A lymph node or lymph gland is an ovoid or kidney-shaped organ of the lymphatic system, and of the adaptive immune system, that is widely present throughout the body. They are linked by the lymphatic vessels as a part of the circulatory system. Lymph nodes are major sites of B and T lymphocytes, and other white blood cells. Lymph nodes are important for the proper functioning of the immune system, acting as filters for foreign particles and cancer cells. Lymph nodes do not have a detoxification function, which is primarily dealt with by the liver and kidneys.
Elephantiasis is the enlargement and hardening of limbs or body parts due to tissue swelling. It is characterised by oedema, hypertrophy, and fibrosis of skin and subcutaneous tissues, due to obstruction of lymphatic vessels. It may affect the genitalia. The term elephantiasis is often used in reference to parasitic worm infections, but may refer to variety of diseases where parts of a person's body swell to massive proportions.
The lymphatic vessels are thin-walled vessels (tubes) structured like blood vessels, that carry lymph. As part of the lymphatic system, lymph vessels are complementary to the cardiovascular system. Lymph vessels are lined by endothelial cells, and have a thin layer of smooth muscle, and adventitia that bind the lymph vessels to the surrounding tissue. Lymph vessels are devoted to the propulsion of the lymph from the lymph capillaries, which are mainly concerned with absorption of interstitial fluid from the tissues. Lymph capillaries are slightly larger than their counterpart capillaries of the vascular system. Lymph vessels that carry lymph to a lymph node are called afferent lymph vessels, and those that carry it from a lymph node are called efferent lymph vessels, from where the lymph may travel to another lymph node, may be returned to a vein, or may travel to a larger lymph duct. Lymph ducts drain the lymph into one of the subclavian veins and thus return it to general circulation.
Paget's disease of the breast is a type of cancer that outwardly may have the appearance of eczema, with skin changes involving the nipple of the breast. The condition is an uncommon disease accounting for 1 to 4.3% of all breast cancers and was first described by Sir James Paget in 1874. The condition in itself often appears innocuous, limited to a surface appearance and it is sometimes dismissed, although actually indicative of underlying breast cancer.
Lymphadenopathy or adenopathy is disease of the lymph nodes, in which they are abnormal in size or consistency. Lymphadenopathy of an inflammatory type is lymphadenitis, producing swollen or enlarged lymph nodes. In clinical practice, the distinction between lymphadenopathy and lymphadenitis is rarely made and the words are usually treated as synonymous. Inflammation of the lymphatic vessels is known as lymphangitis. Infectious lymphadenitis affecting lymph nodes in the neck is often called scrofula.
Chromoblastomycosis is a long-term fungal infection of the skin and subcutaneous tissue. The infection occurs most commonly in tropical or subtropical climates, often in rural areas. It can be caused by many different types of fungi which become implanted under the skin, often by thorns or splinters. Chromoblastomycosis spreads very slowly; it is rarely fatal and usually has a good prognosis, but it can be very difficult to cure. The several treatment options include medication and surgery.
A chylothorax is a type of pleural effusion. It results from lymph formed in the digestive system called chyle accumulating in the pleural cavity due to either disruption or obstruction of the thoracic duct. In people on a normal diet, this effusion can be identified by its turbid, milky white appearance, since chyle contains high levels of triglycerides. It is important to distinguish chylothorax from pseudochylothorax, which has a similar appearance, but is caused by more chronic inflammatory processes, and has a different treatment. The condition is rare but serious. It results from leakage of lymph fluid from the thoracic duct or one of its tributaries. There are many treatments, both surgical and conservative. About 2 to 3 percent of pleural effusions are chylothoraces.
Lymphangiosarcoma is a rare cancer which occurs in long-standing cases of primary or secondary lymphedema. It involves either the upper or lower lymphedematous extremities but is most common in upper extremities. Although its name implies lymphatic origin, it is believed to arise from endothelial cells and may be more accurately referred to as angiosarcoma.
Radical mastectomy is a surgical procedure involving the removal of breast, underlying chest muscle, and lymph nodes of the axilla as a treatment for breast cancer. Breast cancer is the most common cancer among women today, and is primarily treated by surgery, particularly during the early twentieth century when the mastectomy was developed with success. However, with the advancement of technology and surgical skills, the extent of mastectomies has been reduced. Less invasive mastectomies are employed today in comparison to those in the past. Nowadays, a combination of radiotherapy and breast conserving mastectomy are employed to optimize treatment.
Stewart–Treves syndrome, refers to a lymphangiosarcoma, a rare complication that forms as a result of chronic, long-standing lymphedema. Although it most commonly refers to malignancies associated with chronic lymphedema resulting from mastectomy and/or radiotherapy for breast cancer, it may also describe lymphangiosarcomas that result from congenital and other causes of chronic secondary lymphedema. Lymphangiosarcoma arising from cancer-related lymphedema has become much less common with better surgical techniques, radiation therapy, and conservative treatment. The prognosis, even with wide surgical excision and subsequent radiotherapy, is poor.
Malignant histiocytosis is a rare hereditary disease found in the Bernese Mountain Dog and humans, characterized by histiocytic infiltration of the lungs and lymph nodes. The liver, spleen, and central nervous system can also be affected. Histiocytes are a component of the immune system that proliferate abnormally in this disease. In addition to its importance in veterinary medicine, the condition is also important in human pathology.
Lymphoma (lymposarcoma) in animals is a type of cancer defined by a proliferation of malignant lymphocytes within solid organs such as the lymph nodes, bone marrow, liver and spleen. The disease also may occur in the eye, skin, and gastrointestinal tract.
Vulvar cancer is a malignant, invasive growth in the vulva, or the outer portion of the female genitals. The disease accounts for only 0.6% of cancer diagnoses but 5% of gynecologic cancers in the United States. The labia majora are the most common sites involved representing about 50% of all cases, followed by the labia minora. The clitoris and Bartholin glands may rarely be involved. Vulvar cancer is separate from vulvar intraepithelial neoplasia (VIN), a superficial lesion of the epithelium that has not invaded the basement membrane—or a pre-cancer. VIN may progress to carcinoma-in-situ and, eventually, squamous cell cancer.
Chronic progressive lymphedema (CPL) is a disease of some breeds of draft horse, whereby the lower legs becomes progressively more swollen. There is no cure; the aim of treatment is to manage the signs and slow progression of the disease. The cause of CPL is not known, although it is suspected that a genetic disorder of elastin metabolism prevents the lymphatic vessels from functioning properly, leading to edema of the lower limbs. CPL resembles the human disease elephantiasis verrucosa nostra.
Lymphatic disease is a class of disorders which directly affect the components of the lymphatic system.
Milroy's disease (MD) is a familial disease characterized by lymphedema, commonly in the legs, caused by congenital abnormalities in the lymphatic system. Disruption of the normal drainage of lymph leads to fluid accumulation and hypertrophy of soft tissues.
Postinflammatory lymphedema is a condition characterized by swelling of the soft tissues in which an excessive amount of lymph has accumulated, and is caused by repeated bacterial infections.
Cervical lymphadenopathy refers to lymphadenopathy of the cervical lymph nodes. The term lymphadenopathy strictly speaking refers to disease of the lymph nodes, though it is often used to describe the enlargement of the lymph nodes. Similarly, the term lymphadenitis refers to inflammation of a lymph node, but often it is used as a synonym of lymphadenopathy.
