It is a homogeneous, pink mass that replaces lung parenchyma.
Margins are smooth or slightly lobulated.
The upper arrow indicates the cell type that is most frequent in this lesion. The lower arrow indicates another cell type that is frequent in these lesions. Sections were also stained with the elastic van Gieson stain to detect fibrosis. A mild degree of patchy peribronchiolar and interstitial fibrosis was found in addition to a mild alveolitis with increased interstitial chronic inflammation and alveolar macrophages. In a patient with a history of work in construction, it is highly likely that the cores of the ferruginous bodies are asbestos.