Fig. 3

Pathology findings. Microscopic examination of the debridement specimen from right frontal lobe reveals necrotic brain tissue with broad-based ribbon-like pauciseptate hyphae. The angle of branching is wide-angle and greater than other organisms, usually approaching 90° (a and b). Angioinvasion is easily identified (c). There is a marked inflammatory response which is neutrophilic and granulomatous between the viable brain tissue and necrosis (d). a (Periodic acid–Schiff stain) and b (Grocott–Gomori methenamine silver stain): Irregular, broad-based, pauciseptate thick fungal hyphae branching at right angles in the necrotic focus (original magnification, ×400). c Angioinvasion or invasion of the vessels by hyphae. d (Hematoxylin–eosin stain): Granulomatous inflammatory response (original magnification, ×400)