Lymphedema is swelling that occurs when protein-rich lymph fluid accumulates in the interstitial tissue. This lymph fluid may contain plasma proteins, extravascular blood cells, excess water, and parenchymal products. Lymphedema is one of the most poorly understood, relatively underestimated, and least researched complications of cancer or its treatment. The Institute of Medicine of the National Academies published a report in 2006 recommending a "survivorship care plan" for cancer patients that incorporates information about late effects of treatment, health management behaviors, disease management, and recurrence monitoring. The Institute of Medicine also highlighted critical shortfalls in the transition to survivorship, particularly in providing education about late effects of treatment.
Lymphedema is an important consideration for clinicians who care for cancer patients because of its relatively high frequency and significant functional and quality of life implications for patients. Lymphedema is an independent predictor of decreased quality of life, even when other predictive factors such as socioeconomic status, decreased range of motion, age, and obesity are taken into account.
This summary will review issues related to anatomy and pathophysiology of lymphedema related to cancer, its clinical manifestations, diagnosis, and treatment. Primary (congenital) lymphedema and non-cancer-related lymphedema (e.g., recurrent cellulitis, connective tissue disease, and infection) will not be reviewed here.
In this summary, unless otherwise stated, evidence and practice issues as they relate to adults are discussed. The evidence and application to practice related to children may differ significantly from information related to adults. When specific information about the care of children is available, it is summarized under its own heading.
Anatomy and Pathophysiology of the Lymphatic System
The human lymphatic system generally includes superficial or primary lymphatic vessels that form a complex dermal network of capillarylike channels that drain into larger, secondary lymphatic vessels located in the subdermal space. These primary and secondary lymphatic vessels parallel the superficial veins and drain into a deeper third layer of lymphatic vessels located in the subcutaneous fat adjacent to the fascia. A muscular wall and numerous valves aid active, unidirectional lymphatic flow in secondary and subcutaneous lymphatic vessels. Primary lymphatic vessels lack a muscular wall and do not have valves. An intramuscular system of lymphatic vessels that parallels the deep arteries and drains the muscular compartment, joints, and synovium also exists. The superficial and deep lymphatic systems probably function independently, except in abnormal states, although there is evidence that they communicate near lymph nodes. Lymph drains from the lower limbs into the lumbar lymphatic trunk, which joins the intestinal lymphatic trunk and cisterna chyli to form the thoracic duct that empties into the left subclavian vein. The lymphatic vessels of the left arm drain into the left subclavian lymphatic trunk and then into the left subclavian vein. Lymph channels of the right arm drain into the right subclavian lymphatic trunk and then into the right subclavian vein.