Diffuse pulmonary lymphangiomatosis (DLP) is an extremely rare silent disease, characterized by proliferation and thickening of abnormal pulmonary, pleural, and mediastinal soft tissue lymphatic channels. Its clinical presentation is nonspecific symptoms such as cough, dyspnea, and hemoptysis. Tomographic findings for DLP include thickening of the interlobular septa and peribronchovascular interstitium and ground glass opacities. Nevertheless, the anterior mediastinal mass, associated with thickening of interlobular septa and peribronchovascular interstitial, ground glass opacities, pleural effusion, diffuse infiltration of the mediastinum and pleural thickening in a patient with lymphangiomas, DLP should be suspected as a differential diagnosis.