What is malignant mesothelioma? how is it different from benign?

Very: Benign is relatively infrequent, localized and removable . Malignant is "cancer" and expands and invades and spreads and frequently is beyond surgical efforts when found.

Pleural tumor: It affects the pleural membrane around the lung. Mainly caused by asbestos exposure. Many people can have thick plaques in the pleura that doesnt grow rapidly which is known as benign pleural plaques. When it becomes malignant the tumor spreads rapidly engulfing the lungs and causing fluid accumulation.