A patient receiving immunosuppressive therapy after receiving a renal allograft developed ulcers on the lower extremities. Acid-fast bacilli were seen by biopsy but were not demonstrable by culture. The lesions responded to antituberculous drugs. Chaetoconidium was cultured and demonstrated in biopsy specimens of the lesions over an eight-month period.
The organism has been considered a contaminant, but in this patient it was found growing in subcutaneous abscesses. Because of morphologic similarities, this organism may be mistaken in tissue sections for more common fungi.
Stylianos Lomvardias, Gordon E. Madge. Chaetoconidium and Atypical Acid-Fast Bacilli in Skin Ulcers. Arch Dermatol. 1972;106(6):875–876. doi:10.1001/archderm.1972.01620150057017