The characteristic features of HRCT scan in LAM are multiple (>10), well-defined cysts and no other significant pulmonary involvement, such as interstitial lung disease, except for multifocal micronodular pneumocyte hyperplasia in TSC.10 Because multiple cysts appear in lung in some other diseases, such as Langerhans histiocytosis X, pulmonary fibrosis, emphysema, pneumatocele, lymphocytic interstitial pneumonia, and Birt-Hogg-Dube syndrome, LAM should be differentiated according to the clinical findings and the specific radiologic pattern. In LAM, proliferation around the wall of the terminal bronchioles causes small airway obstruction, resulting in air trapping, emphysema, and pneumothorax.18 Proliferation of the smooth muscle cells surrounding the lymphatic vessels causes obstruction and thickening of interstitial tissue, resulting in pleural effusion and interstitial lymphatic edema. However, in some cases, these interstitial changes may be explained by additional factors, such as intercurrent relapsing infections. In the present case, we considered first that the ill-defined parenchymal opacification in the right lower lobe developed from combined nosocomial pneumonia, because the right lung lesion became noticeable during the long-term chylothorax, which might have caused malnutrition and subsequently infection. However, follow-up chest radiographs showed the right lung abnormality worsened gradually as the left chylothorax progressed. In addition, the radiologic finding of the right lung showed an improvement with a resolution of the left chylothorax through chest tube drainage. Therefore, we speculate that the right parenchymal opacification was lymphedema, an uncommon manifestation of LAM.