The clinical characteristics of lower extremity lymphedema in 440 patients.

BACKGROUND: Lower extremity lymphedema is frequently encountered in the vascular clinic. Established dogma purports that cancer is the most common cause of lower extremity lymphedema in Western countries, whereas chronic venous insufficiency (CVI) is often overlooked as a potential cause. Moreover, lymphedema is typically ascribed to a single cause, yet multiple causes can coexist.
METHODS: A 3-year retrospective analysis was conducted of demographic and clinical characteristics of 440 eligible patients with lower extremity lymphedema who presented for lymphatic physiotherapy to a university medical center's cancer-based physical therapy department.
RESULTS: The four most common causes of lower extremity lymphedema were CVI (phlebolymphedema; 41.8%), cancer-related lymphedema (33.9%), primary lymphedema (12.5%), and lipedema with secondary lymphedema (11.8%). The collective cohort was more likely to be female (71.1%; P < .0001), to be white (78.9%; P < .0001), to demonstrate bilateral distribution (74.5%; P < .0001), and to have involvement of the left leg (bilateral, 69.1% [P < .0001]; unilateral, 58.9% [P = .0588]). Morbid obesity was pervasive (mean weight and body mass index, 115.8 kg and 40.2 kg/m2, respectively) and significantly correlated with a higher International Society of Lymphology lymphedema stage (stage III mean weight and body mass index, 169.2 kg and 57.3 kg/m2, respectively, vs stage II, 107.8 kg and 37.5 kg/m2, respectively; P < .0001). Approximately one in three (35.7%) of the population sustained one or more episodes of cellulitis, but patients with stage III lymphedema had roughly twice the rate of soft tissue infection as patients with stage II, 61.7% vs 31.8%, respectively (P < .001). Multifactorial lymphedema was present in 25%. Approximately half of the patients with lipedema with secondary lymphedema (48.1%) or primary lymphedema (45.5%) had a superimposed cause of swelling that was usually CVI. Total knee arthroplasty was the most common cause of noncancer surgery-mediated worsening of pre-existing lymphedema.
CONCLUSIONS: In a large cohort of patients treated in a cancer-affiliated physical therapy department, CVI (phlebolymphedema), not cancer, was the predominant cause of lower extremity lymphedema. One in four patients had more than one cause of lymphedema. Notable clinical characteristics included a proclivity for female patients, bilateral distribution, left limb, cellulitis, and nearly universal morbid obesity.