I. Prevalence

• 1.
  

  Cardiac tumors in the pediatric age group are very rare. A large portion of pediatric primary heart tumors (about 70%) are seen in patients younger than 1 year.

  
  
• 2.
  

  Relative frequency of cardiac tumors in the pediatric age group is shown in Table 14.1 .

  
  
  
  
  • a.
    

    In infants younger than 1 year, more than 50% are rhabdomyomas, followed by fibromas (25%).

    
    
  • b.
    

    In children 1 to 16 years, nearly 40% are fibromas and myxomas.

  
  
  
  

  Table 14.1

  
  

  Relative Incidence of Cardiac Tumors in Infants and Children

  
  

  Adapted from Becker, A. E. (2000). Primary heart tumors in the pediatric age group: a review of salient pathologic features relevant for clinicians. Pediatric Cardiolology, 21 (4), 317-323.

  
  

  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  

  Tumors	Incidence (%)	Tumors	Incidence (%)
  Infant (Less 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/angioma	6	Myxoma	17
  Teratoma	2	Hemangioma/angioma	4
  Others	8	Teratoma	0
  		Others	8
  Malignant Tumors (6%)		Malignant Tumors (43%)
  Rhabdomyosarcoma	2	Rhabdomyosarcoma	8
  Leiomyosarcoma	4	Leiomyosarcoma	2
  Others	0	Others	33

   
  
  
  
  
• 3.
  

  More than 90% of primary tumors are benign in infants.

II. Pathology

Description of three common cardiac tumors follows.

III. Clinical Manifestations

• 1.
  

  Cardiac tumors usually are found on routine echo studies when the diagnosis is not suspected.

  
  
• 2.
  

  Syncope or chest pain may be a presenting complaint in older children. Sudden unexpected death may be the first manifestation. Rarely, symptoms vary with posture in cases of pedunculated tumors (such as myxoma).

  
  
• 3.
  

  Cardiac findings are nonspecific and vary primarily with the location and the size of the tumor.

  
  
  
  
  • a.
    

    Tumors near cardiac valves may produce heart murmurs of stenosis or regurgitation of valves.

    
    
  • b.
    

    Tumors involving the conduction tissue (such as seen with fibromas) may cause arrhythmias or conduction disturbances.

    
    
  • c.
    

    Intracavitary tumors (such as rhabdomyoma) may produce inflow or outflow obstruction.

    
    
  • d.
    

    Mural tumors may result in heart failure or cardiac arrhythmias.

    
    
  • e.
    

    Pericardial tumors, which may signal malignancy, can produce pericardial effusion and cardiac tamponade.

    
    
  • f.
    

    Fragmentation of intracavitary tumors may lead to embolism of the pulmonary or systemic circulations (as seen with myxoma).

  
  
  
  
• 4.
  

  The electrocardiogram may show nonspecific ST-T changes, an infarct-like pattern, low-voltage QRS complexes, or WPW preexcitation. Various arrhythmias and conduction disturbances have been reported.

  
  
• 5.
  

  Chest radiographs may reveal altered contour of the heart with or without changes in pulmonary vascular markings.

IV. Diagnostic Procedures

• 1.
  

  Two-dimensional echo is the primary diagnostic tool. Transesophageal echocardiography (TEE) can provide more precise delineation of the tumor.

  
  
  
  
  • a.
    

    Multiple intraventricular tumors are most likely rhabdomyomas.

    
    
  • b.
    

    A solitary tumor of varying size, arising from the ventricular septum or the ventricular wall, is likely to be a fibroma.

    
    
  • c.
    

    Left atrial tumors, especially when pedunculated, usually are myxomas.

    
    
  • d.
    

    An intrapericardial tumor arising near the great arteries most likely is a teratoma.

    
    
  • e.
    

    Pericardial effusion suggests a secondary malignant tumor.

  
  
  
  
• 2.
  

  TEE can provide more precise delineation of the tumor.

  
  
• 3.
  

  Magnetic resonance imaging (MRI) also provides the same information as the two-dimensional echo study does. MRI techniques have certain advantages over the echo study.

  
  
  
  
  • a.
    

    MRI provides high-resolution images of cardiac cavitary, valvular, myocardial, pericardial, and extracardiac masses, in addition to its relationship with mediastinal and other intrathoracic structures.

    
    
  • b.
    

    It can provide spatial relationship of the tumor mass to the coronary arteries, which may help guide surgical management.

    
    
  • c.
    

    MRI allows differentiation of tumors from myocardium and differentiation of the type of tumor; for example, cardiac hemangiomas from rhabdomyomas and fibromas.

    
    
  • d.
    

    MRI is better than echo in detecting apical tumors.

  
  
  
  
• 4.
  

  Cardiac catheterization and angiography are usually not necessary. Attempts at tissue diagnosis can be risky due to possible embolization of tumor fragment.

V. Management

Surgery is indicated in patients with inlet or outlet obstruction and in patients with symptoms of cardiac failure or ventricular arrhythmias refractory to medical treatment.

• 1.
  

  Rhabdomyomas: Spontaneous regression of these tumors has been well established so that surgical intervention is no longer indicated unless the tumors produce obstruction or arrhythmias refractory to medical treatment.

  
  
• 2.
  

  Fibromas: A successful complete resection of a fibroma is possible. In some cases, the tumor intermingles with myocardial tissue so that complete resection is not possible without causing damage to the myocardium or conduction tissues.

  
  
• 3.
  

  Surgical removal is a standard procedure for myxomas and has a favorable outcome. The stalk of the tumor should be removed completely to prevent recurrence.

  
  
• 4.
  

  If myocardial involvement is extensive, surgical treatment is not possible. Cardiac transplantation may be an option in such cases.