Presumed left atrial myxoma presenting with seizures, massive stroke, and systemic embolization in an adolescent: a case report

Cardiac myxoma (CM) is the most common primary cardiac tumor and, despite its benign histology, may lead to severe and life-threatening complications, primarily due to systemic embolization and intracardiac obstruction. Neurological events, particularly ischemic stroke, can be the initial manifestation and may obscure the underlying cardiac origin, especially in pediatric patients. We report the case of a 14-year-old Persian male who presented with progressive dyspnea on exertion followed by syncope, recurrent generalized tonic–clonic seizures, and rapid neurological deterioration. Initial evaluation at a local center was unrevealing on chest radiography. Following the onset of recurrent generalized tonic–clonic seizures, the patient was initially treated as having a primary seizure disorder before the underlying ischemic stroke and cardiac source of embolism were recognized. He was subsequently admitted to a tertiary pediatric intensive care unit in a critically ill state requiring ventilatory support. Brain computed tomography demonstrated a large right hemispheric infarction with cerebral edema and midline shift. Laboratory findings revealed elevated inflammatory and myocardial injury markers. Electrocardiography showed nonspecific ST-segment changes that were insufficient to establish a diagnosis of acute myocardial infarction. Transthoracic echocardiography identified a large, highly mobile left atrial mass measuring 22 × 55 mm, arising from the interatrial septum and highly suggestive of a left atrial myxoma. The mass intermittently prolapsed into the mitral valve, causing partial obstruction. Severe mitral and tricuspid regurgitation were also present. Doppler ultrasonography confirmed femoral and popliteal arterial thrombosis, indicating systemic embolization. Despite anticoagulation and intensive supportive care, the patient experienced sudden cardiac arrest and died before surgical excision and histopathological confirmation of the mass could be obtained. A cardiac source of embolism, including a left atrial mass highly suggestive of myxoma, should be considered in pediatric patients presenting with acute neurological deficits, particularly when accompanied by systemic embolic phenomena or unexplained cardiopulmonary symptoms. Early echocardiographic evaluation is critical for timely recognition and appropriate clinical decision-making. In the absence of surgical excision and histopathological confirmation, the diagnosis should remain presumptive. Delayed recognition may result in catastrophic neurological and systemic complications and may preclude definitive diagnosis and surgical management.