Disseminated Aspergillus flavus infection presenting as spondylodiscitis: a fatal tuberculosis mimicker in an immunocompetent host - case report and literature review.

INTRODUCTION

Disseminated invasive aspergillosis is a rare but life-threatening fungal infection that predominantly affects immunocompromised individuals. Vertebral involvement is an uncommon manifestation, and diagnosis in immunocompetent patients is particularly challenging because of its nonspecific clinical and radiological features, often resulting in delayed diagnosis and inappropriate therapy. We report a fatal case of disseminated Aspergillus flavus aspergillosis presenting as spondylodiscitis in an immunocompetent host, highlighting the diagnostic challenges and therapeutic implications.

CASE DESCRIPTION: A 54-year-old man with no recognized immunosuppressive condition presented with a five-month history of progressive dorsolumbar pain complicated by paraparesis. Magnetic resonance imaging demonstrated thoracic spondylodiscitis with extensive epidural and paravertebral abscesses. Histopathological examination of the discovertebral biopsy initially suggested tuberculous spondylodiscitis, leading to empirical antituberculous therapy and corticosteroid administration. Mycological culture and periodic acid-Schiff staining subsequently identified an Aspergillus section Flavi isolate phenotypically identified as Aspergillus flavus, establishing the diagnosis of Aspergillus spondylodiscitis. Empirical antifungal therapy with amphotericin B deoxycholate was initiated and later switched to voriconazole after antifungal susceptibility testing showed reduced in vitro susceptibility to amphotericin B and an elevated echinocandin minimum effective concentration, with preserved susceptibility to voriconazole. Additional investigations, including compatible cross-sectional imaging findings and a positive serum galactomannan antigen assay, supported presumed pulmonary and sphenoidal sinus involvement in addition to proven vertebral disease with extension to the adjacent ribs. Evaluation of host immunity revealed negative HIV serology and a preserved CD4 T-lymphocyte count (902 cells/µL), with no identifiable underlying risk factors. Despite targeted antifungal therapy, the patient experienced progressive neurological deterioration due to spinal cord compression, requiring emergency decompressive laminectomy. He subsequently developed postoperative septic shock and died.

CONCLUSION

This case underscores that invasive aspergillosis should be considered in the differential diagnosis of chronic or subacute spondylodiscitis, even in apparently immunocompetent patients. Early diagnosis requires vertebral biopsy with dedicated fungal histopathology, mycological culture, species identification, and antifungal susceptibility testing to enable timely targeted therapy and early multidisciplinary management.