Blastomycosis

Epidemiology and Etiology:

• Normal habitat:
• Soil
• Endemic areas:
• Central and southeastern US
• Canada
• Mexico
• Middle east
• Africa
• India
• Virulence factors:
• Resists phagocytosis

Common sites:

• Upper lobes
• Bronchial

Gross features:

• lobar consolidation
• multilobar infiltrates
• perihilar infiltreates
• multiple nodules
• miliary infiltrates

Histologic features:

• yeast form
• 5-15 microns
• thick, double-contoured cell wall
• multiple nuclei
• broad-based budding
• suppurative granulomas in the normal host
• skin and larynx:
• marked epithelial hyperplasia (mistaken for squamous cell carcinoma)

Immunophenotype:

Marker:

Sensitivity:

Specificity:

Molecular features:

Other features:

• Blastomyces dermatidis
• Bronchial stenosis

References:

• Robbins 2005
• Essentials of AP 2006