CASE PRESENTATION: A 44 year old female complained of exertional dyspnea of 1 month, right chest discomfort, and nonproductive cough. Her exercise tolerance, unlimited 2 months prior, had declined to 1 block. She was treated for CML with Dasatinib 100mg once daily from 2012 to 2016 when she presented with dyspnea. Her exam revealed dullness with egophony over the right lung from base to scapula. Chest radiograph showed a large right pleural effusion, new since her last radiograph 8 months before. Computerized tomography with angiography showed large pleural effusion, parenchymal ground glass opacities, foci of septal wall thickening, no pulmonary embolism, and no hilar/mediastinal lymphadenopathy. Thoracentesis and transthoracic echocardiogram (TTE) were performed. Dasatinib was stopped. To relieve dyspnea, thoracentesis was repeated 13 and 27 days later. Currently, she takes no medication. Pleural fluid characteristics and TTE findings are presented below.