Mucus plug from a patient with bronchocentric granulomatosis

Sputum expectorated by a patient with bronchocentric granulomatosis. The particles present in the sputum were gray-black in color and 0.3 × 0.5 cm in size. On microscopy, the particles were composed of eosinophils and Charcot-Leyden crystals. A silver methenamine stain was negative for fungus.