Retrocardiac lucency with air-fluid level is seen in: (A) Hiatus hernia, (B) Distal end esophageal obstruction, (C) Eventration of diaphragm, (D) Zenker's diveiculum
Answer is A. The gastric fundus when displaced above the diaphragm, presents as a retrocardiac mass on a chest radiograph. The presence of an air-fluid level in the mass suggests the diagnosis. ref - Harrisons internal medicine 20e pg 2211