Figure 10a. ABPA in a 31-year-old asthmatic man with 15% peripheral eosinophilia. (a) Chest radiograph shows tubular and cystic lesions in the central portions of both lungs. Note also the mucus plugging with a gloved-finger appearance (arrows). (b) Thin-section (1-mm collimation) CT scan (lung windowing) demonstrates central bronchiectasis with mucus plugging (arrows), centrilobular nodules, and bronchial wall thickening involving predominantly the segmental and subsegmental bronchi of the upper lobes. (c) Photomicrograph (original magnification, x100; H-E stain) of the impacted mucoid material from a bronchoscopic biopsy specimen reveals parallel rows of necrotic eosinophils and cellular debris within a mucinous background. (d) High-power photomicrograph (original magnification, x400; Gomori methenamine silver stain) shows branching fungal hyphae within impacted mucus, a finding that is suggestive of Aspergillus species.