Case 172. Sporotrichosis (68 y-o M)
Biopsy from painless, red-colored crusted papules on the chest wall
Key words : 
Sporothrix schenckii, sporotrichosis, pseudocarcinomatous hyperplasia, cryptococcosis    
The squamous epithelium shows marked downward proliferation (pseudocarcinomatous hyperplasia) in association with ulceration, marked inflammatory reaction and foreign body giant cell formation (HE, low power).   A few transparent yeast-type fungi are phagocytized by multinucleated giant cells. Active inflammation is associated (HE, high power).
The blastospores phagocytized by the multinucleated giant cells are PAS-positive and show a budding-type growth pattern (PAS).   Reference case 172A
Gross findings of sporotrichosis on the facial skin (8 y-o M). A solitary papule is formed on the face. The localized form of sporotrichosis is often encountered on the child's face, while the lymphangitic form is seen mainly in the upper limb.
Reference case 172A
Immunostaining using 1:500 diluted patient's own serum identifying yeast-type microbes in paraffin section (indirect immunoperoxidase). The patient's serum identifies the pathogens in paraffin section. The serum is widely cross-reactive with many kinds of fungi.
  Reference case 172B
Cutaneous cryptococcosis provoking marked granulomatous reaction in the arm skin of 50 y-o male (HE). Small unstained (transparent) yeast-form fungi are phagocytized by the multinucleated giant cells. The small microbes appear to be floating in the mucoid matrix, and they are alcianophilic.