A 61-year-old man with cough. His past medical history is remarkable only for chronic constipation.
Imaging Findings
(A) Chest radiograph reveals an ill-defined area of parenchymal consolidation in the right upper lobe (arrow). (B, C) Computed tomography (CT) of the chest with two different window levels; within the area of denser opacity, subtle focal hypodensities are noted (arrows).
Differential Diagnosis