Fig. 4

Characteristic pathological findings of indium lung observed in this case. a Cholesterol granulomas, which consist of cholesterol clefts, macrophages and giant cells, were observed in the air space. b In some cholesterol granulomas, fibrosis surrounding the granuloma was observed. c The surface of cholesterol clefts was immunopositive for surfactant protein-A (SP-A). d Black and brown particles contained clear crystal-like particles deposited in the fibrotic stroma or engulfed by macrophages. Surfactant positive for (e) periodic acid-Schiff (PAS) stain and (f) SP-A resided in the entrapped air space. (b)-(f) Bar = 100 μm