A 70 year old man with a history of smoking, COPD, and lung cancer undergoes a pneumonectomy for non small cell lung cancer. His post-operative course is complicated by hemothorax requiring chest tube placement. He eventually is discharged to home. On his routine post-operative visit, he continues to complain of shortness of breath. There is no pleuritic chest pain, cough, or fever. CXR shows an effusion and thoracentesis is performed which has LDH and pleural fluid protein that are borderline between transudate and exudate. WBC is low and predominantly mononuclear. Weeks later, the pleural effusion is back.
A CT is obtained and shown above.
Challenge: What's your diagnosis?
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