A 46-year-old truck driver developed a mycetoma of the left foot after a nail puncture. Soft black granules, 0.5 to 2 mm in diameter, were present in the exudate from draining sinuses as well a in histological sections. Cultural studies led to the identification of the etiologic agent as Madurella grisea. Administration of amphotericin B intravenously failed to control the disease. The mycetoma was ultimately opened, and the superficial sinus tracts were cored out surgically.
Butz WC, Ajello L. Black Grain MycetomaA Case Due to Madurella grisea. Arch Dermatol. 1971;104(2):197-201. doi:10.1001/archderm.1971.04000200085015