Approximately what fraction of mediastinal masses are asymptomatic?

• A. One third
• B. One half
• C. One quarter
• D. Two thirds

Answer: (A)

Many mediastinal masses are found incidentally because they do not cause symptoms, especially when detected on imaging done for other reasons. This makes a sizable portion asymptomatic at presentation. Approximately one third of mediastinal masses fall into this category, while the rest often cause symptoms such as cough, chest pain, shortness of breath, or signs from compression or invasion of nearby structures. Therefore, one third best reflects the typical proportion of asymptomatic mediastinal masses.