Disseminated Cunninghamella bertholletiae Infection From Latent Lower Limb Mass After Kidney Transplant: A Case Report.

Background: Cunninghamella bertholletiae (C. bertholletiae), a rare yet highly virulent species within the Mucorales order, predominantly affects individuals with compromised immune systems. Disseminated infections caused by this pathogen frequently lead to severe complications, underscoring the necessity for prompt diagnosis and aggressive therapeutic interventions. Invasive fungal diseases (IFDs) continue to be a major cause of morbidity and mortality among kidney transplant recipients, characterized by elevated incidence and mortality rates. The early and precise identification of fungal pathogens is crucial for optimizing patient outcomes.

Case presentation: This report presents a case study of a 37-year-old male kidney transplant recipient who developed a disseminated C. bertholletiae infection from a latent lower limb lesion. Initially, he showed symptoms of high fever and dyspnea, leading to diagnoses of sepsis, severe pneumonia, acute respiratory distress syndrome, and allograft dysfunction. After surgery, he had recurrent pleural effusion and worsening pulmonary nodules. Metagenomic next-generation sequencing (mNGS) confirmed C. bertholletiae infection, and histopathology revealed mucormycosis with vascular invasion, thrombosis, and tissue necrosis. The patient underwent a 13-month antifungal treatment with amphotericin B lipid complex, posaconazole, and isavuconazole.

Conclusion: This case highlights the essential role of histopathology and mNGS in early detection of rare IFDs and stresses the need for a multidisciplinary approach combining surgery with antifungal therapy. The effective management of disseminated C. bertholletiae infection using a triple antifungal regimen offers important insights for future cases, underscoring the importance of early diagnosis and personalized treatment in immunocompromised patients.