Central Nervous System Nocardiosis Masquerading as Metastatic Brain Lesions

Abstract Nocardiosis is an uncommon infection, however it needs to be included in the differential diagnosis, especially in immunocompromised hosts. Central nervous system (CNS) nocardiosis, in particular, is an even rarer entity with a higher mortality. This is a case of CNS Nocardia infection with an atypical presentation that was initially concerning for metastatic disease. In an immunocompromised patient with CNS findings, atypical infectious processes need to be considered. In a patient with concomitant pulmonary findings, an evaluation for Nocardia should be pursued as the lungs are the primary route of entry for this organism. Treatment typically involves a sulfonamide with secondary antibiotic agent, however a combination using meropenem has proved effective here.