Introduction rnMalignant pleural effusions ( MPEs) are defined as an abnormal amount of pleural fluid accumulation in the pleural space and are the result of an imbalance between excessive pleural fluid formation and slower pleural fluid absorption.They are caused by a variety of mechanisms including tumor obstruction of lymphatic flow, spread of malignant cells via the systemic circulation, and tumor invasion of the pulmonary arterioles[1] .