Fig. 1

a Chest radiograph demonstrates diffuse ground glass opacities (GGOs) and consolidation in the bilateral lung fields. b CT shows widespread GGOs and consolidation in the dorsal lungs. c, e Follow-up chest radiographs reveal improvement in GGOs and consolidation in the upper and middle lung fields. Multiple thin-walled cysts appear in both middle lung fields (e). d On CT, GGOs and consolidation are improved, and multiple thin-walled cysts containing a small amount of fluid are seen in both upper lobes. f Bilateral cysts have turned into a mass-like opacity. g, h CT shows enlargement of the cysts and exacerbation of GGOs and consolidation in the background of the lungs. Fluid in the cysts show high attenuation, suggesting bleeding