Case 5

This is an HRCT study demonstrating patches of airspace opacification in the upper and mid lung zones bilaterally, which can be characterised by central ground glass opacification surrounded by incomplete rings of consolidation – termed the ‘atoll sign’ or ‘reversed halo sign’; these are mostly peripherally placed.

There are lymph nodes in the mediastinum, showing reactive rather than neoplastic appearance. 

I note sutures at the right lung apex, indicating prior thoracic surgery.

There are no pleural effusions; no nodules or bronchiectasis.

The findings are most characteristic of COP (cryptogenic organizing pneumonia).

However, the atoll sign carries other differential diagnoses, which include atypical infectious pneumonia, drug induced organizing pneumonia, and granulomatosis with polyangiitis.

I would raise this case for discussion at pulmonary MDT.