Congenital abnormalities of the lymphatic system: a new clinical classification

The lymphatic system is the second fluid transport system in the body, accompanying the circulatory system. It removes excessive fluid from tissues, along with small molecules and macromolecules, such as proteins. Difficulties with lymph transport can cause lymphedema (lymph fluid accumulation), and may be due to obstruction or an inadequate transport system. Little detailed information has been available to most general physicians about congenital abnormalities of the lymphatic system, and confusing nomenclature has contributed to the problem. A lymphangioma is a mass of dilated lymph vessels that is thought to be caused by a deformity of the vessels. Lymphangiectasia is a dilation of lymph vessels caused by a malformation or obstruction. These two conditions, both characterized by dilated lymphatics, are difficult to distinguish. The case of a female patient with generalized lymphangiomatosis illustrates the severe complications of lymphatic disorders. At 12 years, the patient developed abdominal pain and swelling, generalized edema, shortness of breath, fever, and sore throat. An abdominal mass was diagnosed as lymphangioma. Pain in the back and other regions resulted from bone lesions, and she also had recurrent respiratory difficulties, persistent abdominal fluid accumulation, abnormal blood clotting, and nutritional problems. Death, at 15 years of age, was due to respiratory failure and possibly infection. The classical pathologic classification of lymphatic abnormalities is presented, and an alternative system, in which lymphatic disorders are described in terms of system involvement, is discussed. These categories include identification of single or multiple soft masses; single or generalized bone lesions; symptoms due to a single abnormal lymphatic function, or a combination of abnormal functions; associated abnormalities, such as clotting disorders; and symptoms related to both lymphatic and circulatory disorders. Medical and surgical treatments have had limited success. Adjustments in the diet may be helpful, and pneumatic pumps to treat leg swelling have also been used. Some disorders of the lymphatics, such as pulmonary or intestinal lymphangiectasia, have a poor outcome and families should be counseled. (Consumer Summary produced by Reliance Medical Information, Inc.)