Effusion under the microscope

A 60 year old gentleman presented with pro-gressively worsening dyspnoea of 8 days in dura-tion. This was associated with a non-productive cough. There was no associated symptoms. There was no history of recent travel. His past medical history was significant for a 60-pack-year smoking history, rheumatoid arthritis diagnosed 6 years pri-or, chronic leg edema and lower extremity ulcers secondary to chronic venous changes. He was treated previously for his rheumatoid arthritis but the treatment was stopped due to poor compliance. Five years prior, the patient underwent thora-centesis for a recurrent right pleural effusion which revealed milky pleural fluid and a diffusely nodular and thickened pleura. Giant multinucleat