Figure 1b. Churg-Strauss syndrome in a 32-year-old woman with clinically suspected bilateral mastitis. The diagnosis of Churg-Strauss syndrome had been established 19 years earlier on the basis of asthma, fever, purpuric cutaneous disease, tachycardia, lung disease, blood eosinophilia, and findings at transbronchial biopsy. (a) Right mediolateral mammogram shows a diffuse increase in parenchymal density. (b) Photomicrograph (original magnification, x400; hematoxylin-eosin [H-E] stain) reveals an inflammation-rich eosinophilic process (arrows) with extensive ductal cellularity (*). (c) Right mediolateral mammogram obtained after corticosteroid therapy demonstrates almost complete resolution of breast involvement.