Echocardiographic diagnosis of intracardiac myxomas. Present status

Cardiac myxomas

Although cardiac myxomas are histologically benign, they may be lethal because of their strategic position. They can mimic not only every cardiac disease but also infective, immunologic, and malignant processes. Myxomas must therefore be included in the differential diagnosis of valvular heart disease, cardiac insufficiency, cardiomegaly, bacterial endocarditis, disturbances of ventricular and supraventricular rhythm, syncope, and systemic or pulmonary embolism. The symptoms depend on the size, mobility, and location of the tumor. Echocardiography, including the transesophageal approach, is the most important means of diagnosis; CT and MRI may also be helpful. Coronary arteriography in patients over 40 years of age is generally required to rule out concomitant coronary artery disease. Surgical removal of the tumor should be performed as soon as possible; the long-term prognosis is excellent, and recurrences are rare. In follow-up examinations as well, echocardiography is essential.

Comparison of transthoracic and transesophageal echocardiography in the diagnosis of intracardiac tumors in adults

To compare transthoracic and transesophageal echocardiography in the diagnosis of intracardiac tumors, 17 patients (8 men and 9 women, aged 19 years to 67 years) whose intracardiac tumors were detected by echocardiography were studied in a 4-year period. Of these, 14 patients underwent cardiac surgery and 13 were proved to have tumors. There were 4 false-positive and 2 false-negative diagnoses by transthoracic echocardiography, but only one false-positive and no false-negative diagnosis by transesophageal echocardiography. The stalk of a myxoma was detected clearly in 5 of 11 patients by transthoracic echocardiography, whereas in 10 of 11 it was detected by transesophageal echocardiography. The detailed morphologic characteristics of the tumor, such as contour of the tumor, and the presence of cysts and calcification in the tumor, were seen more clearly with transesophageal echocardiography than with transthoracic echocardiography.

Invasive development of right atrial myxoma--a case report

A thirty-nine-year-old man was admitted to the authors' department complaining of exertional dyspnea and high fever. An echocardiogram showed a mass in the right atrium, which was observed to move to the right atrium during the systolic phase and to the right ventricle during the diastolic phase. Magnetic resonance imaging showed that the mass developed from the right atrium to the superior vena cava. Intravenous digital subtraction angiography also showed a partial defect of the right atrium as well as obstructions of both the superior vena cava and the bilateral innominate veins. A pulmonary hemodynamic scintigram showed multiple defects at the mid and inferior areas of each lung, suggesting multiple pulmonary infarctions. The right atrial tumor was surgically removed. The superior vena cava and the innominate veins were found to be obstructed by organized thrombi, and the tumor had invasively grown into the right atrial wall. Histologic findings demonstrated that most of the tumor was composed of organized thrombi with scattered myxomatous tissue and was diagnosed as cardiac myxoma. These histologic findings suggest that the histogenesis of this right atrial myxoma might be thrombogenic.

Right atrial myxoma. A cause of septic pulmonary emboli in an adolescent female

An adolescent girl presented with fever, headache, and mental status changes. Blood cultures 12 hours after admission were positive for Staphylococcus aureus. The initial evaluation did not reveal a source of the patient's sepsis. Forty-eight hours after admission a cardiac ejection click was detected. The chest radiograph showed ill-defined opacities compatible with pulmonary emboli in the right lung and a calcific density in the region of the right atrium. Echocardiogram confirmed the presence of a right atrial mass, which at surgery and upon histologic examination was a myxoma. Atrial myxomas are rare tumors in adolescents but should be considered in the differential diagnosis of suspected septic pulmonary emboli.

Echocardiography of Cardiac Myxomas

Myxomas are a rare cardiac tumor usually occurring in the left atrium. Echocardiography has proven to be a valuable noninvasive tool in the diagnosis and followup of cardiac myxomas. A complete M-mode and twodimensional study can be performed to demonstrate motion of the tumor within the heart as well as its position and size. Echocardiography can also aid in the differential diagnosis of mitral valve stenosis, thrombi, and valvular vegetations. When left untreated, cardiac myxomas can be fatal; therefore, identification and prompt surgical removal are essential.

Accessory thyroid tissue in the right ventricle

In an asymptomatic 66-year-old woman presenting a systolic murmur in the pulmonic area, echocardiography evidenced a voluminous mass in the right ventricular outflow tract resembling a cardiac tumor. Histologic finding was that of aberrant normal thyroid. Although the occurrence of ectopic thyroid tissue in the heart is rare, it should be considered in the differential diagnosis whenever a mass is located at the level of the interventricular septum and encroaches on the right ventricular outflow tract. In these cases, a thyroid scintiscan may avoid an unnecessary surgical intervention.

Intracardiac myxomas: twenty-year echocardiographic experience with review of the literature

We reviewed the echocardiograms of 35 patients with intracardiac myxomas. Patient data were combined from two geographically distant laboratories. No significant variations in the patient profiles were encountered. Most patients were white (33 of 35) with a mean age of 45 years. The diagnosis was suspected on clinical grounds alone in only six of 35 patients before the echocardiogram was done. M-mode recordings were the primary echocardiographic modality available in the first 16 patients, whereas two-dimensional studies were also done in the others. Continuous and pulsed wave Doppler echocardiography were added in eight of the most recent studies. In one patient color flow imaging from both transthoracic and esophageal approaches was possible to better visualize a large left atrial tumor. Thirty-three patients had solitary tumors (29 left atrial, three right atrial, and one left ventricular), and two had multiple tumors. The most characteristic finding, as expected, was the demonstration of abnormal mass echoes produced by the myxoma tissue. Several interesting features not previously emphasized in the literature included abnormal notching of the interventricular septum and posterior left ventricular wall probably produced by displacement from the larger mobile left atrial tumors dropping into the mitral sleeve. This was best appreciated by the M-mode recordings. In one patient with an associated atrial septal defect, movement of the tumor into the defect appeared to alter the expected downward displacement into the mitral orifice. In the patients who were studied by two-dimensional, Doppler, or color flow imaging, tumor movement was evidenced by abnormal frequency shifts, and dispersion of flow around the tumor mass was readily appreciated. Surgical removal was performed in all patients. Follow-up echocardiograms were done postoperatively ranging up to 17 years. Recurrent tumors occurred in two patients, both of whom had congenital myxomas. Echocardiography is proving to be an unparalleled tool in the diagnosis of intracardiac tumors.

Hemodynamic consequences of left atrial myxomas as assessed by Doppler ultrasound

Seven patients with left atrial (LA) myxoma who were studied by M-mode, two-dimensional, and Doppler echocardiography and who underwent surgical excision of the tumor are described. In six patients, the myxoma was attached to the lower interatrial septum and was protruding through the mitral valve (MV) during diastole. Significant MV obstruction (mean diastolic gradient of 16 mm Hg) was detected by Doppler in only one patient and was confirmed by hemodynamic studies; another patient had only a small gradient (peak 8 and mean 4 mm Hg). Mild mitral regurgitation (MR) was found preoperatively in four of five patients who underwent left ventriculography, but was not detected by Doppler. Postoperatively, however, five patients were found to have mild MR and one patient had moderate MR by Doppler. The use of Doppler echocardiography can provide important additional information regarding the hemodynamic consequences of LA myxomas.

Osteogenic sarcomas mimicking left atrial myxomas: clinical and two-dimensional echocardiographic features

Two patients presenting with acute pulmonary edema were found to have a left atrial cardiac osteogenic sarcoma (primary and secondary). The two-dimensional echocardiographic appearance in both cases mimicked that of atrial myxoma. However, two echocardiographic features (that is, tumor extension into pulmonary veins and origin from nonseptal atrial walls) suggested the presence of a nonmyxomatous cardiac tumor.

Delay in diagnosis of right atrial myxoma

Clinical, echocardiographic, and nuclear angiographic findings in a 51-year-old woman who presented with a history of dyspnea are discussed. Initial echocardiography revealed no abnormality. However, a subsequent radionuclide angiogram revealed a filling defect on the right side of the heart. This represented a right atrial myxoma. Radionuclide angiography can provide a useful noninvasive tool in the diagnosis of intracardiac tumors when echocardiography has not been helpful.