Pathology
Types and Frequency of Tumors
Table 22-1 shows the relative incidence of cardiac tumors in infants and children ( Becker, 2000 ). Becker’s data include 55 cases from Armed Forces Institute of Pathology, Washington, DC, series 3f, and 21 cases from the Cardiovascular Pathology Registry in the Academic Medical Center, Amsterdam, Netherlands. Data in Table 22-1 show the following.
- 1.
A large portion of primary heart tumors in the pediatric age group presents at less than 1 year of age.
- 2.
The most common cardiac tumor in the pediatric age group is rhabdomyoma. In infants younger than 1 year old, more than 50% of tumors are rhabdomyomas followed by fibromas (25%). In children 1 to 16 years of age, nearly 40% of benign tumors are fibromas and myxomas (see Table 22-1 ). Rhabdomyomas accounted for only 8% of benign tumor in this age group.
- 3.
More than 90% of primary tumors are benign in infants. Although primary malignant tumors are extremely rare in infants (≈5%), approximately 40% of primary tumors were malignant in children older than 1 year of age. Malignant tumors reported in children include rhabdomyosarcoma, leiomyosarcoma, angiosarcoma, fibrosarcoma, and many others.
| Tumors | Incidence (%) | Tumors | Incidence (%) |
|---|---|---|---|
| Infants (younger than 12 months) ( n = 52) | Children (1–16 years of age) ( n = 25) | ||
| Benign Tumors (94%) | Benign Tumors (58%) | ||
| Rhabdomyoma | 52 | Rhabdomyoma | 8 |
| Fibroma | 25 | Fibroma | 21 |
| Hemangioma or angioma | 6 | Myxoma | 17 |
| Teratoma | 2 | Hemangioma or angioma | 4 |
| Others | 8 | Teratoma | 0 |
| Others | 8 | ||
| Malignant Tumors (6%) | Malignant Tumors (43%) | ||
| Rhabdomyosarcoma | 2 | Rhabdomyosarcoma | 8 |
| Leiomyosarcoma | 4 | Leiomyosarcoma | 2 |
| Other | 0 | Other | 33 |
∗ Rearranged data from Becker AE. Primary heart tumors in the pediatric age group: a review of salient pathologic features relevant fro clinicians. Pediatr Cardiol 21:317-323, 2000.
Recently, 120 operated cases of cardiac tumors in infants and children were reported by Bielefeld et al (2012). Although the data are not presented according to two age groups, younger than 12 months and older than 12 months, a similar trend exists with earlier reports. Rhabdomyomas were the most frequent, representing 35% of pediatric cardiac tumors (mean age, 7 months). Myxomas were the second most frequent (23%) with a mean age of 9 years. Fibromas represented 20% of the cases with a mean age of 3.25 years. These three tumor types accounted for three fourths of all surgically treated pediatric cardiac tumors.
Pathology of Individual Cardiac Tumor
Common pediatric cardiac tumors are briefly summarized in this chapter.
Rhabdomyoma
- 1.
Rhabdomyomas are by far the most frequent tumors in the pediatric age group, accounting for about half the cases of cardiac tumors.
- 2.
They usually are multiple, ranging in size from several millimeters to several centimeters. The most common location is in the ventricles, either in the ventricular septum or free wall, but they may rarely appear in the atrium.
- 3.
More than half the children with multiple rhabdomyomas have tuberous sclerosis (e.g., with adenoma of the sebaceous glands, mental retardation, seizures).
- 4.
Tumors regress in size or number or both in most patients younger than 4 years of age (but less so in older patients) ( Nir et al, 1995 ). Spontaneous complete regression may occur.
- 5.
The tumors may produce symptoms of obstruction to blood flow, arrhythmias (usually ventricular tachycardia, occasionally supraventricular tachycardia), or sudden death.
- 6.
Cardiac rhabdomyomas are associated with a higher incidence of Wolff-Parkinson-White (WPW) preexcitation and may increase the risk for arrhythmias.
Fibroma
- 1.
Fibroma is the second most common tumor type encountered in infants and small children.
- 2.
Cardiac fibromas usually occur as a single solid tumor, most commonly in the ventricular septum, although they may also occur in the wall of any cardiac chamber. The size of the tumor varies from several millimeters to centimeters. Occasionally, the tumor calcifies.
- 3.
The tumor may obstruct blood flow and disturb atrioventricular (AV) or ventricular conduction.
- 4.
In some cases, the tumor can be removed completely, but in others, the tumor intermingles with myocardial tissue so that complete resection is not possible. The tumors probably represent hamartomatous lesions that may eventually regress. This has led to a tendency for a less aggressive surgical resection to reduce potential risks for complications.
Myxoma
- 1.
Myxomas are the most common type of cardiac tumors in adults, accounting for about 30% of all primary cardiac tumors, but they are very rare in infants and children.
- 2.
The majority of myxomas arise in the left atrium, 25% arise in the right atrium, and very few arise in the ventricles.
- 3.
Myxomas can produce hemodynamic disturbances, commonly interfering with mitral valve function or producing thromboembolic phenomena in the systemic circulation. With right atrial myxoma, similar effects on the tricuspid valve and thromboembolic phenomena in the pulmonary circulation may be found. Rarely, patients may have symptoms while sitting and standing, but their symptoms improve when they lie down because of the intermittent protrusion of the tumor through the mitral valve.
- 4.
Surgical removal usually is successful.
Teratoma
- 1.
Teratomas contain elements from all three germ layers.
- 2.
Most of the tumors are intrapericardial and are attached to the root of the aorta and pulmonary trunk, but the heart wall can be involved, and occasionally they may present as an intracardiac mass.
- 3.
Surgical excision is usually possible.
Cardiac Angioma
- 1.
This is a relatively rare tumor in infants and children.
- 2.
They show preference for the epicardium, in which they may produce hemopericardium. Intramyocardial location may cause myocardial dysfunction, AV block, or both.
- 3.
They do not grow rapidly, and spontaneous involution has been documented.
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
