Lung nodule caused by Blastomyces dermatitidis

Blastomycosis.
(A) View of the right lower lobe from a computed tomography (CT) image (2.5-mm collimation) shows a triangular nodule in the right lower lobe.
(B) Dynamic CT scans obtained at a similar level to (A) demonstrate marked and persistent enhancement, suggesting an active inflammatory nodule.
(C) Photomicrograph of a wedge resection specimen demonstrates foci of granulomatous inflammation (arrows).
(D) Photomicrograph with Gomori methenamine silver staining reveals yeast forms of Blastomyces dermatitidis. The patient was a 69-year-old woman.