Abstract
INTRODUCTION: Primary cardiac schwannoma (PCS) is an exceptionally rare neurogenic tumor, with only 53 documented cases worldwide. CASE PRESENTATION: We report the case of a 62-year-old woman with a 3-year history of paroxysmal palpitations, who subsequently developed progressive symptoms, such as chest tightness, dyspnea, and dizziness. Diagnostic evaluation revealed supraventricular tachycardia along with a 3.4 × 3.5 cm mass located at the coronary sinus ostium. Multimodal imaging-including echocardiography, CT, and MRI-revealed features characteristic of schwannoma, such as T1 hypointensity, T2 hyperintensity, and peripheral enhancement with internal septations. The patient underwent complete surgical resection of an encapsulated interatrial septal mass measuring 5.0 × 4.0 cm via a right atrial approach, with preservation of cardiac architecture and maintenance of compensatory venous drainage through an accessory ostium. Histopathological analysis confirmed a benign schwannoma exhibiting secondary degenerative changes, supported by positive SOX-10 and S-100 immunostaining and a low Ki-67 proliferation index. At the 3-year follow-up, the patient remained free of recurrence and exhibited no postoperative complications. CONCLUSIONS: This case underscores the diagnostic challenges associated with PCS, particularly in the context of arrhythmias, and emphasizes the importance of multimodal imaging in the preoperative evaluation. The successful surgical resection demonstrates the importance of meticulous surgical planning and technique in managing these rare tumors. This report adds to the limited body of literature on PCS and reinforces the need for a multidisciplinary approach in the diagnosis and management of these complex cases.