Disseminated cutaneous Fusarium infection with vascular invasion in a leukemic patient

A 61-year-old male with leukemia manifested multiple cutaneous nodules on his whole body surface, subcutaneous nodules on his arms and a tongue tumor. Septate hyphae were observed microscopically in scrapings from the surfaces of the cutaneous lesions. Fusarium solani and F. anthophilum were isolated from scrapings from the several skin lesions. Histological examination revealed the presence of numerous septate hyphae in the lumina of vessels in the dermis. The fungal elements in the cutaneous tissues were suggested to be Fusarium by an immunoperoxidase method using a genus-specific anti-Fusarium antibody. Although no evidence of fungal infection was found in other organs by clinical examinations, F. solani and/or F. anthophilum were considered to have undergone hematogenous dissemination, because of the presence of thrombi containing abundant fungal elements in the skin lesion. The present case is a case of disseminated cutaneous Fusarium infection, in which fungal elements in skin tissue sections were immunohistochemically regarded as Fusarium, though fungus cultures from biopsied specimens were negative.