Highlights
We present the first case of successful simultaneous surgical treatment of a patient with breast cancer and a left atrial myxoma. The single-stage surgery, which included a right mastectomy and myxoma removal via a right thoracotomy, was justified by the high embolic risk and allowed for the complete elimination of both life-threatening conditions. The results demonstrate the feasibility of this approach with careful multidisciplinary patient selection and highlight the need for routine echocardiographic screening in the preoperative evaluation of cancer patients.

Abstract
Cardiovascular diseases remain the leading cause of death worldwide. Current data indicate a shift in the patient population, with malignant tumors increasingly common among them. Optimal surgical management for this comorbidity remains unclear, and the feasibility and safety of simultaneous radical treatment have been insufficiently studied. This clinical case demonstrates the feasibility and effectiveness of a simultaneous surgical approach after careful multidisciplinary patient selection. Simultaneous cardiac surgery and oncological intervention allowed for the resolution of both conditions and avoided the risks associated with delayed treatment of left atrial myxoma, particularly embolic complications.