A pleural biopsy is a medical procedure used to collect a small sample of tissue from the pleura, the thin membrane surrounding the lungs. This procedure is often performed when there are abnormal findings in the lungs or pleura, such as fluid accumulation or suspected tumors. The sample helps doctors diagnose conditions like infections, cancer, or inflammatory diseases. The biopsy can be done using different methods, including thoracentesis, where a needle is inserted through the chest wall, or through a small surgical procedure called thoracotomy. The collected tissue is then examined under a microscope to determine the underlying cause of the symptoms.