Presentation
Presented to the GP with chronic cough. Patient had an incidental eosinophilia a year ago.
Patient Data
![](https://prod-images-static.radiopaedia.org/images/2369961/downloaded_image20241208-361684-x6j9l9_big_gallery.jpeg)
Patchy air space opacities in bilateral upper zones.
![](https://prod-images-static.radiopaedia.org/images/2369972/200a2a85bfda00e59d896587a040a09c8993949658ac3363c70b70945f6ec728_big_gallery.jpeg)
Reversed halo pattern (atoll sign): there are round focal areas of ground-glass attenuation with surrounding crescent or ring-shaped consolidation.
Case Discussion
Patient with organizing pneumonia shows a reversed halo pattern (atoll sign) where there are focal round areas of ground-glass attenuation with surrounding crescent or ring-shaped consolidation. This pattern of predominantly peripheral mid and upper zone organizing pneumonia can be seen in chronic eosinophilic pneumonia, a disease that presents with features of pneumonia but responds to corticosteroids. A history of asthma, peripheral blood eosiniphilia and eosinophilia on bronchoalveolar lavage are diagnostic.