Surgical removal of a left ventricular myxoma in an infant
A five-month-old male infant presented with incidental detection of a murmur during an evaluation for upper respiratory tract infection. The child was otherwise symptom-free, with normal growth and development. The examination revealed normal pulse volume and blood pressure. There was no tachypnea. Auscultation of the heart revealed an ejection systolic murmur in the left third intercostal space, radiating to the right second intercostal space. The chest roentgenogram was normal. The child was in sinus rhythm with no echocardiographic (EKG) evidence of LV hypertrophy.\nTransthoracic echocardiography revealed a single tumor mass, with varying echo density, which was 20 mm in its largest dimension, protruding in and out of the left ventricular outflow tract causing significant outflow tract obstruction []. The tumor was arising from the anterior, lateral, and superior aspect involving the lateral papillary muscles. Three-dimensional echocardiography demonstrated an irregular surface []. The Doppler revealed a peak gradient of 88 mmHg across the left ventricular outflow tract. There was no mitral stenosis, mitral regurgitation or aortic regurgitation. The left ventricular function was normal.\nThrough a midline sternotomy and under cardiopulmonary bypass, the aorta was clamped and the left atrium was opened in the Sondergaards plane.[] A vent was introduced and a mitral valve retracted. The tumor was not visualized well from the left atrium. An aortotomy revealed that the tumor was found fully occluding the left ventricular outflow, extending to just below the aortic valve. It was not possible to define the tumor margins and tissue planes completely from the aortotomy.\nA decision was then made to access the LV via the conal septum. The right ventricle (RV) outflow was opened and the conal septum was incised (like in a modified Konno operation) and retracted.[] The tumor was visualized and removed from the superior, lateral, and anterior wall of the LV. Some tumor was left alone in the region of the lateral papillary muscle, as removing it would have damaged the papillary muscle.\nThe tumor on gross appearance was a grayish white tissue with a thin capsule, measuring about 20 × 15 × 8 mm. The histological sections showed a neoplasm with spindle cells having round-to-elongated nuclei, with a vesicular chromatin, and oval-to-elongated spidery cytoplasmic processes, set in a myxoid stroma, along with large areas of hemorrhage, suggestive of a myxoma [].\nThe child was noted to have a complete heart block in the immediate postoperative period that reverted to sinus rhythm spontaneously after – eight days. A pre-discharge echo showed normal ventricular function and a small residual tumor mass in the vicinity of the papillary muscle. At the three-month follow-up there was no increase in the size of the residual tumor. At the six-month follow-up, the child was noted to have a prolonged PR interval, wide QRS interval, and an intermittent Wenckebach phenomenon, on a 24 hour Holter recording. In view of the rhythm abnormality and associated history of the previous transient postoperative complete heart block a permanent pacemaker was inserted into an abdominal pocket. An epicardial lead was used. There was no tumor recurrence at the nine-month follow-up visit.