How is the pleura attached to the lung? can it come off in some diseases?

Visceral / Parietal: The lining (pleura) of the lungs consists of the visceral and pleural lining. There is a virtual (potential) space between the two and they slide back and forth without issues in most people. In a variety of inflammatory states (cancer, pneumonia, chf) fluid can accumulate between these two layers. Treat can include drainage by various methods.