Emerging fungal infection in South West U.S. mimics cancerAn emerging fungal infection of the gastrointestinal tract that mimics cancer and inflammatory bowel disease appears to be emerging in the Southwestern United States and other desert regions, according to Mayo Clinic researchers in Arizona investigating the disease.
The invasive fungus, Basidiobolus ranarum, is typically found in the soil, decaying organic matter and the gastrointestinal tracts of fish, reptiles, amphibians, and bats.
(a) Colonic Basidiobolus ranarum appearing as broad, septate hyphae surrounded by an eosinophilic sheath (Splendore–Hoeppli phenomenon) and numerous eosinophils.
(b) Broad fungal hyphae of B. ranarum (periodic acid–Schiff diastase stain).
(c) Multinucleated giant cells phagocytosing fungal zygospores. The latter appear as spherical bodies that measure up to 30 m m in diameter. They have a thin outer wall, foamy cytoplasm, and a nucleus containing a large nucleolus (haematoxylin and eosin stain).
(d) Broad, septate fungal hyphae (black; Grimelius methenamine silver stain).
Basidiobolus ranarum is a filamentous fungus with worldwide distribution.
The fungus was first isolated by Eidam in 1886. It can saprophytically live in the intestines of mainly cold-blooded vertebrates and on decaying fruits and soil.
The fungus prefers glucose as a carbon source and grows rapidly at room temperature.
Microscopic view of a mycelium. This image covers a one-millimeter