Figure 1: These images demonstrate a fairly classic appearance of parenchymal blastomycosis. There is a large, cystic lesion with smooth rim enhancement demonstrated before and after contrast (top row), normal diffusivity in the cavity on DWI/ADC (middle row) and a mild amount of surrounding vasogenic edema on T2/FLAIR (bottom row). More commonly, these patients will present with meningitis (not presented here).

Description

• Caused by the dimorphic fungus Blastomyces dermatitidis
• Endemic to Ohio and the Mississippi river valley
• Lung infection with hematogenous spread to the CNS in 5-10% of cases of disseminated infections

Pathology

• Exists as a mold in the environment and a yeast at body temperatures

Clinical Features

• Symptoms
  • Nonspecific
  • Headache, AMS, fever, vision...