Approach Considerations
Obtain blood cultures to evaluate the possibility of endocarditis.
On electrocardiography, nonspecific changes and/or left-axis deviation might occur. Repolarization abnormalities, similar to those found in persons with myocardial infarction or ischemia, are secondary to disruption of normal conduction patterns by electrically silent tumor or localized ischemia from tumor compression.
On chest radiographs, findings are often unremarkable. Enlargement of the cardiac silhouette or mediastinal widening might be present. Focal cardiac calcifications are often suggestive and can be characteristic of a fibroma, especially in children.
Echocardiography
Echocardiography plays a fundamental role in the evaluation of patients with embolic complications, unexplained cardiac murmurs, or signs and symptoms of heart failure. [5]
Cardiac echocardiography represents the best diagnostic test for evaluating patients with history and/or physical examination findings suggestive of valvular dysfunction or the possibility of an intracardiac mass. [1, 4, 8] The ability to distinguish tissue characteristics, location, morphology, and mobility noninvasively, quickly, and without the use of ionizing radiation makes echocardiography the ideal diagnostic modality.
Equivocal transthoracic findings typically indicate the need for a transesophageal evaluation, during which the atria and great vessels might be better imaged.
Surgical intervention is often indicated based on echocardiographic findings, without the need for additional time-consuming, costly, or invasive studies.
Magnetic Resonance Imaging
Once a cardiac mass is identified, magnetic resonance imaging (MRI) can be extremely beneficial in determining the extent of tumor involvement and cellular characteristics. [1, 9, 10, 11]
T1- and T2-weighted images often provide valuable clues regarding tissue characterization; spin-echo image intensities can help differentiate cardiac tumors.
Although MRI cannot definitively distinguish between benign and malignant tumors, this imaging modality may help to identify characteristics more common in malignant cardiac masses, such as larger size and more frequent demonstration of contrast first-pass perfusion and late gadolinium enhancement compared to benign masses. [10] A tissue diagnosis is required in order to determine whether tumors are benign or malignant.
Cardiac MRI (CMRI) may also be highly accurate in differentiating cardiac thrombi from tumors. [10, 12]
Several small studies have suggested that MRI might be more sensitive and specific for primary cardiac tumors than echocardiography, but no large studies have demonstrated a benefit of MRI over echocardiography.
With equivocal echocardiographic findings, MRI might help differentiate an intracavitary tumor from a thrombus or hypertrophied papillary muscle.
CT Scanning
Computed tomography (CT) scanning is often performed during an evaluation for a possible thoracic malignancy, and findings might suggest a primary cardiac tumor. [1, 13] CT scan findings might provide clues regarding tissue characterization, with central calcification suggestive of a cardiac fibroma.
However, even with advances in electrocardiographic (ECG) gating, cardiac CT scanning often offers little diagnostic value over a thorough echocardiographic evaluation.
Angiography with Cardiac Catheterization
In patients with known intracardiac masses, ventriculography is relatively contraindicated because of the significant risk of catheter-induced tumor embolization.
In patients who possibly are at high risk for concomitant coronary disease and are undergoing surgical treatment, simple coronary angiography might be necessary.
If a mass is found as an incidental finding during angiography, take strict care to minimize disruption of the mass to avoid causing a systemic embolic complication.
Ventriculography might demonstrate filling defects suggestive of an intracavitary mass.
Histologic Findings
Myxomas are similar to pluripotent germ cells with acid mucopolysaccharide matrix. The cells appear spindle or polygonal shaped.
Microscopically, fibromas are a light-gray, complex interlacing of dense collagen with occasional fibroblasts. Cardiac fibromas are similar to fibromas found in other soft tissue locations, except for the lack of a distinct capsule. Fibromas can contain myocardial fibers, but these are believed to reflect entrapment of myoblasts during tumor growth rather than tissue invasion. Overall, growth tends to displace myocardial tissue rather than invade or destroy it.
-
Benign Cardiac Tumors. Resected left atrial myxoma.
-
Benign Cardiac Tumors. Resected cardiac fibrosarcoma.
-
Benign Cardiac Tumors. Large epicardial cardiac lipoma.
