The yeast form of Blastomyces dermatitidis is a large, 10-15 µm in diameter, thick-walled yeast cell that characteristically produces a single bud attached by a broad base.
Coccidioides immitis does not produce a yeast form in laboratory culture; rather, is identified in stained tissue sections by the production of varying sized spherules, ranging from 10 µm to over 100 µm in diameter. The larger, more mature spherules contain spherical endospores ranging from 2-4 µm in diameter.
Paracoccidioides brasiliensis also produces large yeast cells approximately the same size as those of Blastomyces dermatitidis, except multiple buds are attached by narrow necks, giving the appearance of a “mariner’s wheel“.
The yeast forms of Sporothrix schenckii are elongated cells that have been called “cigar bodies“.