Thank you for choosing health care magic! I appreciate your patience. Plueral effusion could be because of many medical conditions. It could be either an Infection or heart failure
or malignancy. Only microscopic , microbiological and biochemical examinations of the pleural fluid can determine the cause. Enlargement of lymphnodes
could be caused by either infection or malignancy. Some times physicians opt for lymph node biopsy
for definitive diagnosis. Discuss with your physician regarding the biopsy of lymph node and pleural fluid. He is the right person to talk about your condition in detail. Wish you a speedy recovery.