Chylothorax means pleural cavity containing
**Core Concept**
Chylothorax refers to the abnormal accumulation of lymphatic fluid, specifically chyle, in the pleural cavity. This condition arises due to the disruption of the thoracic duct, which is responsible for draining lymphatic fluid from the abdominal and pelvic regions into the bloodstream. As a result, the pleural space fills with a milky or cloudy fluid rich in lymphocytes, triglycerides, and other nutrients.
**Why the Correct Answer is Right**
Chylothorax occurs when the thoracic duct is injured or compromised, allowing lymphatic fluid to leak into the pleural space. This can be due to various causes such as trauma, surgery, cancer, or tuberculosis. The leaked chyle contains a high concentration of triglycerides, which can lead to complications like malnutrition and coagulopathy if left untreated. The presence of lymphocytes and other lymphatic cells in the pleural fluid is a hallmark of chylothorax.
**Why Each Wrong Option is Incorrect**
**Option A:** Air - This is incorrect because air in the pleural cavity is known as pneumothorax, not chylothorax.
**Option B:** Blood - This is incorrect because blood in the pleural cavity is known as hemothorax, not chylothorax.
**Option C:** Purulent fluid - This is incorrect because purulent fluid in the pleural cavity is known as empyema, not chylothorax.
**Clinical Pearl / High-Yield Fact**
Chylothorax can be differentiated from other pleural effusions by the presence of a milky or cloudy fluid with a high triglyceride content (>110 mg/dL). This can be confirmed by a pleural fluid analysis, which also shows a high lymphocyte count and a low glucose level.
**Correct Answer: D. Chyle**