Surgical Resection of an Atypical Right Atrial Free-Wall Myxoma Mimicking Venous Thrombus in a Long-Term Hemodialysis Patient: A Case Report and Surgical Approach

Primary cardiac tumors are rare, with atrial myxomas accounting for the majority of benign lesions. Most myxomas originate from the interatrial septum within the left atrium; attachment to the right atrial free wall is an exceedingly uncommon entity. We report the case of a 52-year-old female patient with chronic kidney disease on long-term hemodialysis via a central venous catheter who presented with persistent lower extremity edema of six months' duration. Transthoracic echocardiography performed at a primary care facility identified an intracardiac mass located near the junction of the inferior vena cava and the right atrium. Given the patient's long-term catheter use, differential diagnosis included intracardiac thrombus versus neoplasm. The patient was transferred to our tertiary center and underwent successful surgical resection via median sternotomy and cardiopulmonary bypass. Intraoperative examination revealed an expansive myxomatous mass arising from the right atrial free wall, adjacent to the inferior vena cava and coronary sinus. Full surgical excision with a 2-cm margin was achieved, followed by primary atrial reconstruction. Histopathological evaluation confirmed an atrial myxoma with clear surgical margins. The postoperative course was uneventful, and the patient showed complete resolution of edema with no tumor recurrence at the 6-month follow-up. This case emphasizes the diagnostic challenges in hemodialysis patients and underscores the necessity of complete surgical excision for atypical right atrial tumors.