TABLE 5.

Types of systemic infection and their features on histology sections (19, 20, 21, 22).

Disease	Causative organism	Clinical features	Histological features
Candidiasis	Candida albicans, Candida species	Invasive and disseminated infection occurs in seriously ill and immune compromised patients	Budding yeast cells (3–5 μm), hyphae and pseudohyphae (constriction occurs where there are septa). C. glabrata does not produce hyphae
Cryptococcosis	Cryptococcus neoformans, Cr. gatii	Pulmonary infection, dissemination in the immune compromised, meningitis in AIDS.	Small yeasts (4–10 μm) budding from a narrow base, mucopolysaccharide capsule stains well with mucicarmine. Fontana Masson stain useful for acapsular variants
Histoplasmosis	Histoplasma capsulatum, H. capsulatum var. duboisii	Pulmonary disease, dissemination in immune compromised. H. duboisii disseminates to skin and bone, Africa	Small (2–4 μm) round to oval yeasts, budding from a narrow base, may be clustered intracellularly. H. duboisii are larger (8–15 μm) budding yeasts
Blastomycosis	Blastomyces dermatiditis, B. gilchristii	Pulmonary disease. Dissemination possible	Large thick walled yeasts (8–15 μm) that bud from a broad base
Paracoccidioidomycosis	Paracoccidioides brasiliensis, P. lutzii	Pulmonary disease. Dissemination especially mucocutaneous	Large yeast cells (15–30 μm) with multiple budding—ship’s wheel appearance
Coccidioidomycosis	Coccidioides immitis, C. posadasii	Acute or chronic pulmonary disease, lung cavities form, dissemination possible in immune competent and immune compromised	Thick walled spherules (10–100 μm) containing endospores (2–5 μm) in different stages of development, granulomatous reaction
Talaromycosis	Talaromyces marneffei	Pulmonary infection, mainly immune compromised. Dissemination	Small oval or curved yeast like cells that divide by transverse fission forming a thick septum. May be clustered inside macrophages
Emergomycosis (Emmonsiosis)	Emergomyces (Emmonsia) pasteurianus, Es. africanus, Es. canadensis, Es. orientalis, Es. europaeus	Pulmonary infection with dissemination, immune compromised hosts	Yeast-like cells (2–7 μm)