Nocardia beijingensis Brain Abscess in an Immunocompetent Host in Malaysia: A Rare Diagnostic Challenge

Introduction: Cerebral Nocardia beijingensis infection is a rare disease that primarily affects immunocompromised hosts. While only a limited number of cases have been reported globally in immunocompetent individuals, none have been documented in Malaysia. In immunocompetent patients, cerebral nocardiosis can radiologically mimic a fatal malignancy, potentially leading to a delay in definitive therapy. Case Report: A 54-year-old man with cerebral nocardiosis was initially misdiagnosed with high-grade glioma and defaulted on the referral to our hospital. Nearly 3 months later, he presented to the emergency department with worsening symptoms. Surgical intervention provided tissue and pus samples for microbiological examination, which yielded N. beijingensis susceptible to standard antimicrobial therapy. The brain abscess was surgically removed, and the patient was treated with systemic antibiotics. The symptoms and radiology findings showed significant improvement following the interventions. Conclusion: This is the first reported case of a brain abscess caused by N. beijingensis in an immunocompetent host in Malaysia, initially misdiagnosed as a malignancy. This case highlights the importance of considering nocardial infections in the differential diagnosis of cerebral lesions, even in immunocompetent individuals. Surgical intervention plays a crucial role in obtaining a definitive diagnosis, as some cases may be effectively treated with a combination of surgery and antimicrobial therapy.