Experimental cutaneous protothecosis in mice: epithelioid cell granuloma formation.

Prototheca wickerhamii, isolated from skin biopsy specimens of a patient with cutaneous protothecosis, were cultured in Sabouraud's medium and inoculated in the skin of 8 ICR albino mice and 3 BALB/c mice. Only in 3 ICR albino mice and 3 BALB/c mice were organisms found in skin tissue, as confirmed by identification of organisms by staining with periodic acid-Schiff (PAS) stain and culture. Histologic findings from affected nodular skin lesions indicated epithelioid cell granuloma and histiocytic cell infiltrates in the dermis and subcutaneous tissue.