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Key Points
Intracardiac tumors are extremely rare in fetuses, occurring in 0.11% to 0.14% of fetal echocardiographic studies.
Most fetal intracardiac tumors (60%-80%) are due to rhabdomyoma. Other causes (in order of decreasing frequency) are teratoma, fibroma, vascular tumors, and myxoma. If multiple tumors are present, the diagnosis is almost always rhabdomyoma.
Sixty to ninety-five percent of cases of rhabdomyoma are due to tuberous sclerosis, an autosomal dominant disorder.
Antenatal management includes evaluation of fetal cardiac function and determining if dysrhythmias are present.
Hydrops and dysrhythmias are associated with in utero demise. Overall, there is a 66% survival rate for fetuses with intracardiac tumors.
Genetic consultation, examination of parents and siblings, fetal brain MRI, and level II sonography are all indicated to rule in or rule out tuberous sclerosis.
Delivery should occur at a tertiary center.
Most tumors regress postnatally, but if surgical removal is necessary, the postoperative prognosis is excellent.
Tuberous sclerosis is associated with relatively high rates of new mutation and gonadal mosaicism, so the affected fetus/neonate should undergo DNA testing to both confirm diagnosis and provide a definitive means of prenatal diagnosis in future pregnancies.
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The most common intracardiac tumors found in fetuses, infants, and children are rhabdomyomas (Abushaban et al., 1993; Holley et al., 1995). Rhabdomyomas can involve the myocardium, endocardium, pericardium, papillary muscles, cardiac valves, and the pulmonary and aortic outflow tracts (Gava et al., 1990). Rhabdomyomas occur with equal frequency in the right and left ventricles. In 30% of cases, one or both atria are involved (Deeg et al., 1990).
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Tuberous sclerosis is a neurocutaneous disorder resulting from hamartomatous growths that can occur in any organ. Interestingly, there is an age-related presentation of the lesions in different organs in tuberous sclerosis (Kwiatkowski and Short, 1994). Rhabdomyomas are primarily the fetal manifestation of tuberous sclerosis (Bader et al., 2003). The classic presentation of tuberous sclerosis, however, is later in life, when the hallmark findings are facial angiofibromas, seizures, and mental retardation.
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Overall, intracardiac tumors are extremely rare in infants and children. In one series of children presenting to a pediatric cardiology referral unit, 0.08% had an intracardiac tumor as their referring symptom. Cardiac tumors are found in 0.0017% to 0.25% of pediatric autopsies (Groves et al., 1992). The most likely diagnosis for an intracardiac tumor is rhabdomyoma.
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The incidence of intracardiac tumors has been estimated from antenatal sonographic studies. In a series of 794 congenital cardiac malformations derived from more than 10,000 fetal scans, 11 cardiac tumors were identified (0.11%) (Groves et al., 1992). Similar numbers were reported by Holley et al. (1995), who identified 19 fetuses with intracardiac tumors in ~ 14,000 fetal echocardiographic reports (=0.14%).
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