Primary Lymphedema: Anatomically Isolated or a Pervasive Systemic Disorder?

Background: Primary lymphedema, a condition characterized by impaired lymphatic function, has long remained underexplored. Current diagnostic approaches rely on clinical history and genetic testing, yet the genetic underpinnings remain elusive in many cases. Traditional thinking suggests that primary lymphedema is confined to specific anatomical regions, but our experience challenges this notion. We hypothesize that primary lymphedema is systemic lymphatic dysfunction. Methods: All patients with clinical diagnosis of primary lymphedema from January 2020 to April 2022 were included in our study. Demographic data, medical and surgical history, and indocyanine green (ICG) lymphographic findings were collected. Results: A total of 152 patients met our inclusion criteria. We observed a predominance of female patients (75%) and a mean age of 43.9 years. The onset of swelling varied, with most patients (82.3%) experiencing it in their lower extremities. Notably, ICG lymphography revealed abnormal lymphatic findings in all symptomatic limbs, affecting multiple extremities in 97.4% of patients. Importantly, even among patients initially presenting with limited symptoms, asymptomatic extremities exhibited lymphatic defects. In addition, the extent of lymphatic disease, assessed through ICG lymphography, surpassed clinical symptoms in 80% of cases, underscoring the systemic nature of primary lymphedema. Conclusions: Our study suggests that primary lymphedema is a systemic lymphatic insufficiency, affecting the entire lymphatic system. This underscores the importance of comprehensive assessments, even with limited symptoms, to facilitate earlier diagnosis and more effective treatment approaches.