Plugging of airways with mucus

A. Necrotic mass prolapsing in and out of the distal right intermediate bronchus obscuring both the basal stem and basal division

Initially it was incorrectly diagnosed as a bronchial carcinoma.
The material was allergic mucin with mucus and cellular debris arranged in a layered pattern. Cellular debris was almost entirely eosinophils with scattered Charcot-Leyden crystals. A Grocott stain showed multiple branching fungal hyphae, consistent with Aspergillus spp. Subsequently her total IgE rose to  750 KIU/L and Aspergillus specific RAST to 14.9 KUa/L.