Which pleural pathology involves lymph accumulating in the pleural space?

• A. Hydrothorax
• B. Chylothorax
• C. Pleural effusion
• D. Hemothorax

Answer: (B)

Lymph accumulating in the pleural space is chylothorax. This happens when the thoracic duct or other lymphatics are disrupted, allowing chyle to leak into the pleural cavity. Chyle is rich in triglycerides and lymphocytes, so the effusion is often milky and triglyceride-rich, which helps distinguish it from other fluid types. This differs from hydrothorax, which is fluid in the pleural space due to systemic or hydrostatic issues like heart failure or hypoalbuminemia; pleural effusion is the broad term for any fluid in the space without specifying its cause; and hemothorax is blood in the pleural space typically from trauma or vascular injury. Therefore, the pathology described as involving lymph in the pleural space is chylothorax.