Correct!

4. An intracavitary mass superimposed on a background of interstitial abnormality

Frontal and lateral chest radiograph shows a mid- and upper lung predominant linear and reticular abnormalities with architectural distortion. A nodule (arrow) is seen projected over the right upper lung, and appears to reside within a thin-walled cavity (arrowheads).

Clinical Course: The patient underwent thoracic CT (Figures 2A and 2B).

Figures 2A and B: Axial (A) and coronal (B) thoracic CT

Click here for a movie of axial CT images       Click here for a movie of coronal CT images

What is the main finding on the thoracic CT?

1. Upper lobe predominant bullae
2. Traction bronchiectasis
3. Calcified hilar and mediastinal lymph nodes are present
4. A cavity containing a nodular opacity
5. All of the above