In our paper 1, we summarised the expertise and practical guidelines we have built in recent years for the differential diagnosis and management of focal ground-glass opacities (GGOs) detected by spiral computed tomography (CT), either in a screening programme or incidentally.
As J-J. Hung and co-workers rightly point out, malignant GGOs may show a mixed evolution pattern over time with a decrease in their overall size but an actual increase of the central solid component. This should not be mistaken for a regression, but rather for progression to solid adenocarcinoma 2. Regression in response to antibiotic trial was defined by us as fading or disappearance of the entire lesion, which occurred in five (12.5%) cases.
Six patients were evaluated retrospectively, as their GGOs were visible on previous CT scans months before the lesion was actually reported. Antibiotics were not prescribed at that point as we did not expect them to have an effect on such lesions. …