Cryptococcosis

Figure 4.33 A: Cryptococcus neoformans (Courtesy of Doctor Fungus, www.doctorfungus.org) B: Mucormycosis (Courtesy of Dr. Paul Getz) C: Mucor spp.* D: Rhizopus spp .* *Courtesy of Sandra Arduin, Michigan Department of Community Health
Figure 4.33
A: Cryptococcus neoformans
(Courtesy of Doctor Fungus,
www.doctorfungus.org
)
B: Mucormycosis
(Courtesy of Dr. Paul Getz)
C: Mucor spp.*
D: Rhizopus spp .*
*Courtesy of Sandra Arduin,
Michigan Department of
Community Health
(Figure 4.33A)
  • Cryptococcus neoformans, dimorphic fungus with characteristic polysaccharide capsule, found in pigeon droppings, soil, and dust
  • Transmission via inhalation
  • Presentation:
    • Primary pulmonary infection: asymptomatic or mild infection in an immunocompetent person, but immunocompromised person may have disseminated disease (can spread to CNS, bone, skin); secondary skin lesions are polymorphous (molluscum-like umbilicated papules, acneiform pustules, papules, nodules, abscesses, etc.)
    • Primary cutaneous infection (inoculation): extremely rare
  • Histology: encapsulated yeast (2–12 µm), ± single or budding, mucoid capsule stains well with mucicarmine, PAS, Alcian blue; India ink stains yeast (capsule appears as clear halo)
    • Gelatinous pattern: numerous budding yeast, capsule does not stain which gives dermis vacuolated gelatinous appearance, minimal inflammation
    • Granulomatous pattern: pseudoepitheliomatous hyperplasia, granulomatous infiltrate with fewer yeast
  • Treatment: amphotericin B ± flucytosine