My father has malignant cells in his lung fluid, what is the treatment?

Q: From the past one month, my father is not able to eat. He says he is getting chest pain. We went to a doctor who said that the lungs are surrounded by fluid and is not able to see the lungs through an X-ray. Then they took out some fluid using syringe and sent that fluid for analysis. The fluid analysis report shows that it contains malignant cells. Then CT scan was done and reporting that lungs are fine. Also other parts - kidney, liver and entire abdomen are clean. The blood results are also normal. What will be reason for secretion of fluid? What treatment he can take? For his treatment, to which specialist he has to consult? Please help me.

A:It appears your father has a hidden malignancy which has spread to the pleural cavity and is causing this fluid. The primary source could remain hidden despite best attempts and I do not consider it worthwhile testing further for it in this situation unless the pathologist says that lymphoma is a possibility. No specific therapy is likely to be of much benefit. The fluid may need to be drained to help ease any breathing difficulty. In case it accumulates repeatedly and causes breathing difficulty, manoeuvres like instilling some substances in the pleural cavity may be useful.