Pulmonary blastomycosis refers to respiratory infection with the organism Blastomyces dermatitidis. It is a pyogranulomatous fungal infection and the respiratory system is the commonest site of infection with this organism. The disease is endemic to North America.
There can be marked variation in presentation ranging from from asymptomatic infection to rapidly severe and fatal disease. Most will present as an acute to chronic pneumonia or may be discovered as a lung mass like opacity on a radiograph .
While individual features are non specific, several radiographic patterns have been described which include air-space disease, nodular opacities, mass like lesions, interstitial disease, cavitation (37% ) and military disease . The air space consolidation and mass like opacities may have an upper lobe predilection .
Lymphadenopathy and pleural effusions may be uncommonly present.