Disseminated mucormycosis leading to a fatal gastrointestinal perforation in a pediatric case of EBV-associated Hemophagocytic lymphohistiocytosis.

Disseminated mucormycosis is a rare and often fatal infection, primarily affecting immunocompromised individuals. Its diagnosis is extremely challenging, as definitive identification of organisms in tissue by histopathology with culture confirmation can be invasive, slow, and insensitive. We present the case of a 12-month-old female with Hemophagocytic Lymphohistiocytosis (HLH), triggered by a high Epstein-Barr virus (EBV) viral load and complicated by an underlying NK-cell perforin deficiency. Despite rapid HLH-specific and maximal supportive care, the patient developed life-threatening mucormycosis with extensive gastrointestinal involvement. Clinicians should note insidious signs, such as a black eschar and hypodense lesions on MRI imaging findings, indicative of tissue infarction from hyphal vascular invasion in these susceptible hosts. Prompt invasive testing of involved organs is critical upon suspicion.