Histoplasma Capsulatum

This micrograph depicts the histopathologic changes associated with histoplasmosis of the spleen using Gridley stain, 1964. Positive histoplasmin skin tests occur in as many as 80% of the people living in areas where Histoplasma capsulatum is common, such as the eastern and central United States. Note the many yeast forms of H. capsulatum within histiocytes. Image courtesy CDC/Dr. Martin Hicklin. (Photo by Smith Collection/Gado/Getty Images).