Differential diagnosis of lower extremity enlargement in pediatric patients referred with a diagnosis of lymphedema.

BACKGROUND There are many causes for a large lower limb in the pediatric age group. These children are often mislabeled as having lymphedema, and incorrect diagnosis can lead to improper treatment. The purpose of this study was to determine the differential diagnosis in pediatric patients referred for lower extremity "lymphedema" and to clarify management. METHODS The authors' Vascular Anomalies Center database was reviewed between 1999 and 2010 for patients referred with a diagnosis of lymphedema of the lower extremity. Records were studied to determine the correct cause for the enlarged extremity. Alternative diagnoses, sex, age of onset, and imaging studies were also analyzed. RESULTS A referral diagnosis of lower extremity lymphedema was given to 170 children; however, the condition was confirmed in only 72.9 percent of patients. Forty-six children (27.1 percent) had another disorder: microcystic/macrocystic lymphatic malformation (19.6 percent), noneponymous combined vascular malformation (13.0 percent), capillary malformation (10.9 percent), Klippel-Trenaunay syndrome (10.9 percent), hemihypertrophy (8.7 percent), posttraumatic swelling (8.7 percent), Parkes Weber syndrome (6.5 percent), lipedema (6.5 percent), venous malformation (4.3 percent), rheumatologic disorder (4.3 percent), infantile hemangioma (2.2 percent), kaposiform hemangioendothelioma (2.2 percent), or lipofibromatosis (2.2 percent). Age of onset in children with lymphedema was older than in patients with another diagnosis (p = 0.027). CONCLUSIONS "Lymphedema" is not a generic term. Approximately one-fourth of pediatric patients with a large lower extremity are misdiagnosed as having lymphedema; the most commonly confused causes are other types of vascular anomalies. History, physical examination, and often radiographic studies are required to differentiate lymphedema from other conditions to ensure the child is managed appropriately.