Multiple fragments of hemorrhagic, red-tan soft tissue and portions of thin, translucent cancellous bone were received. Histologic examination revealed numerous polypoid fragments (Images 03 and 04) of respiratory epithelium overlying mucoid stroma infiltrated with numerous eosinophils, lymphocytes, plasma cells, mast cells and neutrophils. Some polyps showed a prominent thickening of the basement membrane (Image 05). Small fragments of bone were dispersed among these tissue fragments. In addition, copious mucous debris (Images 06 and 07) with numerous degenerating eosinophils and Charcot-Leyden crystals was present. Grocott stains revealed numerous septated, hyphal fungal forms (Images 08, 09, and 10) and rare yeast forms throughout the fragments of polyps and the mucus.
Gray to black fungal colonies were identified on blood agar, CNA, Inhibitory mold agar (IMA) (Image 11), and Brain-heart infusion agar (BHI). Germ tube test revealed profuse conidiation with conidia that showed 3-5 septa and a slightly protruding hilum (Image 12). The germ tubes formed on the end cells of the conidia and were oriented along the axis of the conidium (Image 13). The morphology was consistent with Bipolaris spp.