In what conditions might you expect to see irregular mass lesions with or without calcification in the upper lobes on CT?
Sarcoid, previous tuberculosis (TB), and in cases with previous exposure to silica dust.
Are the CT findings characteristic of acute/subacute hypersensitivity pneumonitis?
The conglomerate mass lesions seen in the upper lobes are not a feature of acute or subacute HP, which are also called non-fibrotic hypersensitivity pneumonitis. The nodular pattern involving the peripheral interstitium is also not typical for HP (nodules along the pleura/fissures).
Normal heart size and shape. Normal pleurae and pericardium. No bone lesions.
Multiple small non-calcified nodes.
There are multiple nodules present in all segments of both lungs, centrilobular, subpleural, and along interlobar fissures. No cavitation of the nodules seen. In addition, there are areas of more conglomerate mass formation seen particularly in the upper zones. These are associated with changes of lung distortion and fibrosis. No subpleural reticulation or interlobular septal thickening is noted. Some areas of air trapping/mosaic attenuation are noted bilaterally.