The potential space existing between the pleural surfaces.
Small space between the visceral and parietal layers of the pleura.
The potential space between the visceral and parietal pleura. In some diseases and conditions the space fills with air, blood, lymph, or malignant tumors. Air in the pleural space is called pneumothorax. Blood in the space is called hemothorax. Lymph accumulations in the pleural space are called chylothorax. Malignant tumors that may fill the pleural space include mesothelioma or metastatic lung or breast cancers, among others.
The narrow gap that exists between the two layers of the membrane encompassing the lungs and lining the inner surface of the chest is referred to as the pleural cavity.