Somayyeh Sadeghi - M.D, Assistant Professor of Pulmonology Department of Pulmonary Diseases, Al-Zahra Hospital, Isfahan University of Medical Sciences, Isfahan, Iran

Certain tumors appear to have a predilection for metastasis to the pleura, particularly lungcancer, breast cancer, and lymphomas, and less commonly gastrointestinal and genitourinarymalignancies . In approximately half the cases of metastatic pleural disease, the patient will have anassociated pleural effusion, most often exudative. However, in up to 10% of the malignant pleuraleffusions, the tumor of origin is never identified.Malignancies probably produce pleural effusions by both increasing the entry of liquid anddecreasing the normal exit of liquid . The entry of liquid can increase by several mechanisms: (1)increased permeability of the pleural vessels by direct invasion of tumor cells, inflammatory andvasoactive cytokines (e.g., vascular endothelial growth factor [VEGF]), or injury (e.g., radiationinduced);(2) increased permeability of pulmonary vessels by infection, pulmonary embolism, orpulmonary infarct with movement of liquid from lung to pleural space; (3) increased hydrostaticforces due to venous obstruction or hypoproteinemia; and (4) entry of other sources of liquid suchas chyle from a disrupted thoracic duct. The exit of liquid from the pleural space can decrease byseveral mechanisms that would reduce lymphatic drainage: (1) infiltration of parietal pleurallymphatics or mediastinal lymph nodes, (2) lowered pleural pressure due to atelectasisWhen clinicians encounter a patient with an MPE, they frequently ask:●What is the prognosis ●Should the effusion be treated ●What are the treatment options ●How do I know which option is best I present a 42 year old woman is evaluated for chest pain and mild dyspnea from 2 weeksago.• She is diagnosed with receptor- negative breast cancer 1 years ago and is status post rightmastectomy followed by chemotherapy and radiation. Her pain is resistant to NSAID. Chestradiograph shows pleural effusion in right side…….• We try to answer the above question