Pediatric Cardiac Tumors Workup

• CBC count with differential should be normal in benign cardiac tumors. In malignant tumors, any kind of blood count abnormality can be present in these patients. For example, anemia is not an uncommon finding. Platelet count may be elevated or low, and WBC count may be high.
• Erythrocyte sedimentation rate (ESR) is a nonspecific marker for inflammation that may be normal or elevated; however, the ESR could be low in the presence of congestive heart failure (CHF).
• Liver function test findings are occasionally elevated because of severe right-sided heart failure or metastases.
• Creatine kinase-myocardial band (CK-MB) fraction levels have been found to be higher in patients who have both ventricular dysfunction and a cardiac tumor but not necessarily primary malignancies from the heart.

• Echocardiography

  • This is the most cost-effective of all tests used to evaluate the anatomy of the heart. Echocardiography can provide important information about size, extension and/or invasion within and outside the heart, valvar involvement and/or competency, ventricular function, and pericardial effusion. Refer to the following images Echocardiographic parasternal long-axis view showing a large mass within the left ventricular cavity invading or connected to the anterior mitral valve leaflet. AO=Aorta, RV=Right ventricle, LA=Left atrium, Arrow=Left ventricular mass. Echocardiographic subcostal view of a patient with a large mass within the left ventricular cavity invading or connected to the anterior mitral valve leaflet. Mass within the left ventricle fills most of the ventricular cavity. LA=Left atrium, RA=Right atrium, RV=Right ventricle, Arrow=Left ventricular mass. Echocardiographic parasternal long-axis view demonstrating a rounded mass in the area of the right ventricular outflow tract. Mass was not causing any outflow obstruction. RV=Right ventricle, LV= Left ventricle, AO=Aorta, Arrow=Right ventricular mass. Echocardiographic apical 5 chamber view of a 1 month old patient with several ventricular tumors filling the ventricular cavities in both sides. The patient was having seizures and diagnosed to have tuberous sclerosis. The tumor associated with this disease is rhabdomyoma (see text). RA= Right Atrium; Ao= Aorta; LA= Left Atrium; RV= Right Atrium; LV= Left Ventricle Follow-up echocardiographic 4 chamber view from the same patient as shown in the image above. This echocardiogram was done 8 months after the previous view. Note that the tumors have changed in size and some of them have regressed totally, especially in the right ventricle. The arrows show the remaining areas of tumors seen in both ventricles.
  • It is very sensitive but not specific.
  • Some of these tumors may be too small for echocardiographic detection, especially those leading to dysrhythmias.
  • Transesophageal echocardiogram also is useful in detecting tumors in the left heart, especially in adults.
• Chest roentgenography: Cardiomegaly and pulmonary edema may present in cases of obstructive lesions. Certain neoplasms can have calcium deposition detected on the roentgenogram.
• MRI: MRI is a powerful tool in diagnosing tumors, evaluating their extent, and seeking metastases.^[4] It may delineate the area of the mass better than echocardiography because it has a larger field of observation. Contrast enhancement and multislice imaging can provide a 3-dimensional view of tissue. It also can help differentiate tumors from thrombi.
• CT scanning: Ultrafast CT scanning is gaining use in this area because it eliminates artifacts of heart motion seen with conventional CT scanning. CT is a powerful tool in evaluating the extent of the tumor and exhibits a high degree of tissue discrimination.
• Nuclear medicine studies are used in children to evaluate congenital and developmental disorders of the chest. The same radiopharmaceuticals and imaging techniques are used to evaluate pediatric patients as are used in adults to evaluate cardiac and pulmonary disease, aerodigestive disorders, and pediatric malignancies.^[5]

• ECG: Nonspecific changes are the most common findings; however, ST-T segment changes with strain patterns have been noticed in obstructive rhabdomyomas and fibromas. After surgery, these changes return to normal. Other patterns associated with ischemia also may be present. Diffuse low-voltage QRS, especially in the presence of pericardial effusion, can be seen. Arrhythmias may be the first presentation of an intracardiac tumor and occasionally are resistant to medical therapy. Other findings include intraventricular conduction delay and complete bundle branch block.

• Endomyocardial biopsy is controversial and seldom useful in children because of the high possibility of false-negative results and the high possibility of metastasis during the procedure if a malignant tumor is present.

Benign tumors

Rhabdomyomas are a glycogenic degeneration of myocardial fibers and are thus considered hamartomas. They contain large vacuolated cells filled with glycogen. Their microscopic hallmark, the spider cell, displays eccentric nuclei, granular cytoplasm with a central cytoplasmic mass, and fine fibrillar processes that radiate to the periphery, giving the appearance of a spider in a web. Because the cytoplasm is rich in glycogen, it stains positive with periodic acid-Schiff reagent. Rhabdomyositis is a rare form of cardiomyopathy. In this pathology, microscopic changes in the muscle and conduction system are evident, yet gross anatomic findings are rare.

Cardiac fibromas consist of elongated fibroblasts, with fibrous tissue and collagen. Occasionally, calcium can be seen using radiography or microscopically within the tumor. Mitosis is rarely seen in this type of tumor.

Myxoma has a characteristic pattern of cells termed lipidic cells embedded in a myxoid stroma rich in glycosaminoglycans. These cells are multinucleated with pink cytoplasm. Typically, they present in clusters surrounding vascular structures. Calcium is present in approximately 10% of patients. Usually, the embolized material has a different pattern from the material at the center of the lesion, and cells resemble embryonic mesenchymal cells, similar to embryonic endocardial cushion tissue.

Teratomas, rarely malignant in children, form from 3 embryonic tissues that usually grow in the anterior mediastinum. These tumors should be differentiated from intrapericardial bronchogenic cysts because they may have the same gross appearance; the histologic difference is that bronchogenic cysts do not contain neuronal tissue, which is usually present in teratomas.

Hemangiomas are classified, based on the predominant type of proliferating vascularity, into hemangiomas (common) or lymphangiomas (extremely uncommon). The tumor contains endothelium-lined spaces that may have blood, lymph, or thrombi.

Malignant tumors

Angiosarcomas have variable vascular channels lined with atypical endothelial cells.

The histologic hallmark of rhabdomyosarcoma is the presence of cross-striations.

Fibrosarcomas are composed of a herringbone pattern of spindle-shaped cells with elongated blunt-ended nuclei and frequent mitoses.