On chest radiograph, a patient has a central, well-defined, round opacity that is clearly within the mediastinum and forms an acute angle with the mediastinal border. This opacity moves with swallowing. Which is the most likely structure?
- A Pericardial cyst
- B Substernal thyroid ✓
- C Bronchogenic cyst
- D Neurogenic tumor
Correct answer: B. Substernal thyroid
Explanation
A substernal thyroid mass is a mediastinal opacity that moves with swallowing due to its attachment to the thyroid gland and trachea via the pretracheal fascia. Pericardial and bronchogenic cysts are typically lower mediastinal masses that do not move with swallowing. Neurogenic tumors arise in the posterior mediastinum near the spine and do not move with deglutition.
Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.