Question: A 28-year-old male presents with sudden-onset chest pain and shortness of breath. He has no significant medical history. A chest X-ray is performed, which is shown below. What is the most likely diagnosis?
Options:
A) Pulmonary embolism
B) Pneumothorax
C) Acute myocardial infarction
D) Pneumonia
E) Pleural effusion
Image: Chest X-ray showing a large pneumothorax on the right side with a visible pleural line and absent lung markings beyond the pleural line.
Answer: B) Pneumothorax
Explanation: A pneumothorax occurs when air enters the pleural space, causing collapse of the affected lung. On a chest X-ray, the hallmark finding is a visible pleural line without lung markings beyond it, as seen in this patient. The condition can result from trauma, spontaneous rupture of a bleb, or underlying lung disease. It is important to recognize this finding early, as large pneumothoraces may require intervention, such as chest tube placement.
Simon Downes, MD, PhD 