What is the classic tissue morphology of Coccidioides species in tissue?

What is the classic tissue morphology of Coccidioides species in tissue?

• A. Spherules containing endospores
• B. Septate hyphae with arthroconidia
• C. Yeast-like budding cells
• D. Fungal granules with chlamydospores

Answer: (A)

In tissue, the hallmark of Coccidioides is large, thick-walled spherules filled with numerous endospores. These spherules can rupture to release endospores, which fuels the local inflammatory response and disseminates infection. This tissue form is what sets Coccidioides apart from its mold form seen in culture, which consists of septate hyphae with arthroconidia. The other described forms—yeast-like budding cells or fungal granules with chlamydospores—belong to different fungi or contexts and do not represent the characteristic tissue morphology of Coccidioides.

In tissue, the hallmark of Coccidioides is large, thick-walled spherules filled with numerous endospores. These spherules can rupture to release endospores, which fuels the local inflammatory response and disseminates infection. This tissue form is what sets Coccidioides apart from its mold form seen in culture, which consists of septate hyphae with arthroconidia. The other described forms—yeast-like budding cells or fungal granules with chlamydospores—belong to different fungi or contexts and do not represent the characteristic tissue morphology of Coccidioides.