Invasive Saprochaete capitata Infection in an Immunocompromised Patient With Acute Myeloid Leukemia: A Case Report

Saprochaete capitata (S. capitata) is a rare but emerging opportunistic fungal pathogen, identified as an arthroconidial yeast-like filamentous fungus. It can cause potentially life-threatening invasive fungal infections (IFIs) in immunocompromised patients, particularly those with hematological malignancies and profound neutropenia, and is associated with poor clinical outcomes. Diagnosing invasive S. capitata infections is challenging, relying primarily on clinical suspicion and isolation of the pathogen from blood, other sterile body fluids, or tissue biopsies. Due to its resistance to both echinocandins and fluconazole, S. capitata presents significant treatment challenges, with no established optimal therapeutic strategy for invasive infections. Here, we present a case of a 46-year-old man with acute myeloid leukemia who developed an invasive S. capitata infection with fungemia and pulmonary involvement during post-chemotherapy aplasia. Despite profound immunocompromise, the patient successfully recovered following treatment with combination antifungal therapy, which included liposomal amphotericin B and voriconazole. This case highlights the critical importance of early diagnosis and prompt initiation of appropriate antifungal therapy, particularly in immunocompromised patients, to reduce the exceptionally high mortality and morbidity associated with this severe IFI.