Adult-Onset Primary Lymphedema: A Clinical-Lymphoscintigraphic Study of 26 Patients

Background: Primary lymphedema results from the anomalous development of the lymphatic system that typically presents during infancy, childhood, or adolescence. Adult-onset primary lymphedema is rare and has not been studied. The purpose of this investigation was to characterize patients with primary lymphedema that developed after the pediatric time period to better understand the condition. Study Design: Patients treated in our Lymphedema Program between 2009 and 2018 were reviewed. Diagnosis was determined based on history, physical examination, and imaging studies. Patients with primary lymphedema developing in adulthood (>21 years) were identified. Sex, age of onset, location, severity, morbidity, family history, associated features, and lymphoscintigraphy findings were documented. Results: Twenty-six patients (10%) of 259 with primary lymphedema developed the disease during adulthood. Sixteen individuals were female, and the disease occurred at an average age of 40 years (range, 24-72). It affected the lower extremity (85%) (unilateral 82%, bilateral 18%) or upper limb (15%) (unilateral 80%, bilateral 20%). Twenty-seven percent of patients suffered infections. Ninety-five percent of lymphoscintigrams exhibited delayed transit of radiolabeled tracer and 73% showed dermal backflow. None of the patients had systemic lymphatic involvement or associated vascular anomalies. One patient had a family history of lymphedema. Conclusions: Adult-onset primary lymphedema is typically unilateral, affects the lower extremity, and is not associated with systemic lymphatic anomalies; hereditary transmission is rare. Because adult-onset lymphedema is much less common than the pediatric condition, the disease should be confirmed with lymphoscintigraphy. Imaging of the axillary or inguinal nodes is also considered to rule out a lesion causing secondary lymphedema.