Subacute hypersensitivity pneumonitis versus respiratory bronchiolitis

Case contributed by Dr Michael P Hartung


Shortness of breath.

Patient Data

Age: 60 years
Gender: Male

Centrilobular micronodules and mosaic attenuation diffusely throughout both lungs, with perhaps a slight upper lobe predominance.

Mild hilar lymphadenopathy.

Case Discussion

This case nicely illustrates the overlapping appearances of subacute hypersensitivity pneumonitis and respiratory bronchiolitis. Given the absence of a strong smoking history, hypersensitivity pneumonitis is favored in this case. However, both can be characterized by centrilobular micronodules, groundglass opacities, and mosaic attenuation/air trapping. Respiratory bronchiolitis tends to have a stronger apical predominance, with hypersensitivity pneumonitis more pronounced in the mid and lower lung fields.

In this case, both diagnoses belong in the differential, and the clinical workup, follow-up, and treatment can be determined with pulmonology care.

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Case information

rID: 59393
Published: 7th Apr 2018
Last edited: 14th Aug 2019
System: Chest
Inclusion in quiz mode: Included

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