Non-traumatic necrotizing fasciitis caused by Bacillus cereus in a child with acute lymphoblastic leukemia: a case report and proposed gastrointestinal-to-hematogenous pathway

BACKGROUND: Bacillus cereus (B. cereus) is generally considered a self-limiting foodborne pathogen but can cause severe invasive infections in immunocompromised hosts. Necrotizing fasciitis (NF) due to B. cereus is exceedingly rare, particularly in pediatric oncology patients. Moreover, hematogenous NF without antecedent trauma is uncommon, and its pathogenesis remains poorly understood. This case is reported to highlight a potential gastrointestinal-to-hematogenous route of infection and its clinical implications. CASE PRESENTATION: A 10-year-old boy with acute lymphoblastic leukemia developed fulminant, non-traumatic NF and septic shock during chemotherapy-induced myelosuppression. The illness began with gastrointestinal symptoms after food intake and rapidly progressed to extensive soft tissue necrosis and circulatory collapse. B. cereus was isolated from both blood and tissue cultures. Due to profound neutropenia, severe thrombocytopenia, coagulopathy, and hemodynamic instability, immediate radical surgical debridement was considered prohibitively risky. The patient was initially treated with broad-spectrum antimicrobial therapy, intensive organ support, and correction of coagulopathy. Following clinical stabilization, staged surgical debridement and vacuum-assisted closure were performed. The patient recovered and was able to resume leukemia treatment. CONCLUSION: This case expands the clinical spectrum of invasive B. cereus infection and suggests a potential paradigm in which gastrointestinal translocation may lead to hematogenous NF in immunocompromised hosts, even in the absence of trauma. It underscores the importance of early recognition, multidisciplinary collaboration, and individualized decision-making regarding surgical timing. Further studies are warranted to better define the pathogenesis and optimal management strategies for this rare but life-threatening condition.