A patient with previously diagnosed lung cancer develops a large pleural effusion. The effusion is tapped and demonstrates an unusual milky white fluid that upon standing, separates into a thin white layer over a thicker clear layer. The lipid content of the fluid is high. This is most likely an example of which of the following?

The fluid is lymphatic fluid. A large tumor in the chest can damage the thoracic duct, allowing the chylomicron-rich lymphatic fluid from the abdomen to drain into the pleural cavity (chylothorax) rather than the vena cava.Exudates are fluids produced by lesions such as bacterial infections that contain more protein than does serum; transudates are filtrates of serum. Fibrinous pleuritis is characterized by deposition of fibrin on the pleural surface. Fibrous pleuritis is characterized by deposition of collagen and formation of connective tissue along the pleural membranes.