Case Report: Recurrent cerebral embolism secondary to direct cardiac invasion by lung adenocarcinoma.

Background: Recurrent cerebral embolism due to direct cardiac invasion by lung cancer is exceedingly rare yet clinically significant, representing a convergence of neuro-oncologic and cardiogenic stroke mechanisms. Case description: A 41-year-old woman presented with acute right-sided hemiparesis and aphasia. Imaging revealed left middle cerebral artery occlusion, treated successfully with mechanical thrombectomy. Four days later, she developed a second embolic stroke in the right middle cerebral artery (MCA) territory-again resolved via thrombectomy. Further evaluation uncovered a right lung adenocarcinoma infiltrating the pericardium, pulmonary vein, and left atrium. The patient received systemic chemotherapy and anticoagulation. No subsequent embolic events occurred during follow-up. Conclusion: This case demonstrates a rare but important cause of recurrent cerebral embolism-direct cardiac invasion by malignancy-and highlights the efficacy of thrombectomy in cancer-associated large-vessel occlusion. Clinicians should maintain high suspicion for tumor-related stroke in atypical embolic presentations, especially in younger individuals without conventional risk factors.