Final answer:
The most common primary cardiac tumor in children is rhabdomyoma. Although they can occur in any part of the heart, they most commonly occur in the ventricles.
Step-by-step explanation:
The most common primary cardiac tumor in children is rhabdomyoma.
Rhabdomyomas are benign tumors that originate from cardiac muscle cells.
They are usually detected during prenatal ultrasounds or in early infancy.
Although they can occur in any part of the heart, they most commonly occur in the ventricles.