Retropertioneal tumor is demonstrated by lymphangiography in a 28 year old woman with lymphedema of both legs. Retroperitioneal tumor was subtotally extirpated, with subsequent subsidence of the swelling of both legs. According to the pathologic examination of the extirpated specimens, lymphangiomyomatosis was confirmed. This is the fisrt case reported in the literature of lymphangiomatosis presenting with lymphedema of the leg in the absence of pulmonary involvement, pleural or abdominal effusion.