Multiple brain abscesses occur in <15% of immunocompetent patients and  often present without focal neurological deficits, delaying diagnosis. Infected cardiac myxomas are exceedingly rare, with < 50 cases reported . These tumors  can cause systemic embolism,  including septic emboli leading to brain abscess formation, but reports remain anecdotal.

Describe an exceptionally case of multifocal brain abscesses caused by septic emboli from an infected mitral myxoma in an immunocompetent patient,  underscoring diagnostic challenges when blood cultures remain persistently negative.

A 48-year-old previously healthy man presented with headache, fever, and altered mental status. Brain MRI revealed >50 enhancing lesions across cortical, subcortical, and cerebellar regions. Echocardiography demonstrated a mitral valve mass initially interpreted as vegetation. Despite six weeks of empiric intravenous antibiotics and subsequent oral therapy, residual active lesions persisted. Surgical excision identified a cardiac myxoma rather than endocarditic vegetation. All blood cultures remained negative. Following resection and prolonged antibiotics, brain MRI demonstrated complete resolution. Neurocognitive testing improved to Montreal Cognitive Assessment score 26 at follow-up.

Infected cardiac myxomas, though exceedingly rare, must be recognized as a potential source of embolic brain abscesses in immunocompetent patients. When cultures are negative and neurological signs subtle, high clinical suspicion, advanced imaging, and timely surgical intervention are essential to prevent recurrent embolic events and optimize outcomes.