American Board of Surgery Qualifying Exam (ABS QE) Practice Test 2025 - Free Surgery Exam Practice Questions and Study Guide

Increased lymphocytes and triglycerides greater than 110 mg/dL in a pleural effusion are indicative of chylothorax. Chylothorax occurs when lymphatic fluid accumulates in the pleural space, typically due to a disruption of the thoracic duct or obstruction of lymphatic drainage. This condition is commonly associated with trauma, malignancy, or certain surgeries that affect the lymphatic structures.

The presence of triglycerides in the effusion is a hallmark for diagnosing chylothorax, as the lymphatic fluid contains high concentrations of fat and triglycerides due to its origin from the intestinal lymphatics. The predominant lymphocytes in the effusion also suggest an accumulation of lymphatic fluid, reinforcing the diagnosis of chylothorax.

In contrast, pneumothorax does not typically present with increased lymphocytes or triglycerides, as it involves air in the pleural space rather than fluid. Hemothorax is associated with blood in the pleural cavity, leading to different fluid characteristics, and empyema is characterized by infected pleural effusions that show more neutrophils rather than a predominance of lymphocytes. Thus, the combination of increased lymphocytes and elevated triglycerides is specifically indicative of