Unilateral Pleural Effusion – Differential Diagnosis

History: 70 year old male with shortness of breath and cough. 

The differential diagnosis for unilateral pleural effusion includes parapneumonic effusion, neoplasms such as mesothelioma, primary lung cancer, pleural metastases, lymphoma, other entities such as cirrhosis, pancreatitis, and trauma. This patient had a parapneumonic effusion.