Angioinvasive Fusarium and concomitant Enterococcus infection arising in association with leukemia cutis

Leukemia cutis represents the cutaneous infiltration of neoplastic leukocytes or their precursors that results in clinically identifiable skin lesions. For patients with myelodysplastic syndrome, developing such a lesion may indicate impending leukemic transition. These patients are also often immunocompromised, putting them at risk for infection by opportunistic fungal pathogens such as Fusarium. We describe an 85-year-old man with myelodysplastic syndrome who presented with a reddish-purple nodule with a surrounding erythematous plaque on his shin. Histopathologic examination revealed a dense diffuse infiltrate of large atypical cells in the reticular dermis, with ulceration and necrosis. Immunohistochemical studies showed positive staining with CD15, CD68 and myeloperoxidase of constituent large cells. Concurrently, there were branching and septate hyphae with occasional macroconidia-like structures throughout the infiltrate. Cultures from this lesion grew Fusarium and Enterococcus, supporting the diagnosis: leukemia cutis with superinfection involving both Fusarium and Enterococcus. To our knowledge, this is a novel report of two separate infections occurring in a lesion of leukemia cutis. This case shows that in patients with a hematologic malignancy and skin lesions, a high index of suspicion for infection is necessary when reviewing both the clinical and histopathological data to avoid overlooking an important occult infectious agent.