Septic arthritis as breakthrough invasive fusariosis after cord blood transplantation

A 63-year-old male received a third allogeneic hematopoietic stem cell transplantation with voriconazole prophylaxis for relapsed acute myeloid leukemia. He developed septic arthritis without any typical skin lesions due to fungal infection on day 42. Treatment with liposomal amphotericin B was initiated following surgical debridement; however, he died of progressive fungal infection. Ribosomal DNA sequencing identified Fusarium solani species complex (FSSC) harboring voriconazole resistance. This clinical course indicates that breakthrough invasive fusariosis (azole-resistant FSSC infection) needs to be considered as a pathogen when patients with hematological malignancies develop septic arthritis without typical skin lesions during voriconazole prophylaxis.