Authors: David Fitzgerald, MD and Destiny F. Chau, MD - Arkansas Children’s Hospital/University of Arkansas for Medical Sciences, Little Rock, AR
A 1-month-old boy who is born with multiple intracavitary left ventricular tumors presents for follow-up cardiac evaluation. A transthoracic echocardiogram demonstrates multiple masses of homogeneous appearance without inflow or outflow obstruction that are reduced in size from previous imaging. Delta waves are noted on the electrocardiogram. Which of the following cardiac tumors is the MOST likely diagnosis?
EXPLANATION
Primary cardiac tumors in children are rare with a reported incidence of up to 0.4%, excluding inflammatory masses, thrombi, and vegetations. Although most congenital cardiac tumors are benign (90%), the degree of involvement with or invasion into surrounding cardiac structures can lead to detrimental physiologic consequences.
The most common type of cardiac tumor in children is rhabdomyoma, accounting for over 60% of cases. Morphologically, these tumors are well circumscribed, multiple, and often located in the ventricles, either in an intramural or intracavitary position. On echocardiographic images, rhabdomyomas appear echogenic and homogenous. As many of these tumors regress spontaneously, an initial conservative, observational approach to management is appropriate unless the tumors cause hemodynamically significant sequelae. Both atrial and ventricular arrhythmias can occur in 40% of cases. Specifically, the incidence of Wolff-Parkinson-White syndrome is ten-fold that of the general population. Rhabdomyomas are known to be associated with tuberous sclerosis, an autosomal dominant multi-systemic disease affecting the brain, kidney, liver, and lungs. The drugs sirolimus and everolimus have been shown to reduce tumor size in the heart and brain, thus offering a potential alternative to surgical resection.
The second most common type of cardiac tumor in children is fibroma, accounting for 10-25% of cases. Unlike rhabdomyomas, fibromas are solitary tumors that typically do not regress. They tend to grow slowly, typically reaching maximal size in late gestation and early infancy. They are usually located in the interventricular septum or on the ventricular free wall. Fibromas are echogenic, well circumscribed, and often have areas of calcification or cystic degeneration. Fibromas often grow into the conduction system and may cause ventricular tachycardia or sudden death.
Myxomas are rare in neonates but account for approximately 10% of cardiac tumors in older children. They are the most common cardiac tumor in adults. They are most commonly located in the left atrium arising from the fossa ovalis. Morphologically they appear sessile or pedunculated and lobular with frond like projections. Myxomas do not recede but rather require resection. The morphological appearance, typical location in the left atrium and later presentation in life tend to make these lesions easily identifiable. Clinically significant, intermittent obstruction of left ventricular inflow across the mitral valve can occur, as can embolization.
In the stem, the patient has multiple tumors with a characteristic echocardiographic appearance and history of regression over time that is most consistent with a cardiac rhabdomyoma. Fibromas may have a cystic appearance, are solitary and do not regress. Myxomas are usually present in older children, are typically located in the left atrium, and do not recede.
REFERENCES
Uzun O, Wilson DG, Vujanic GM, Parsons JM, De Giovanni JV. Cardiac tumours in children. Orphanet J Rare Dis. 2007;2:11.
Marx G, Moran A. Cardiac tumors. In: Shaddy R, Penny D, Feltes T, Cetta F, Mital S, eds. Moss & Adams’ Heart Disease in Infants, Children, and Adolescents: Including the Fetus and Young Adult. 10th ed. Philadelphia: Lippincott Williams and Wilkins; 2022:1639-1644
McKenzie I, Markakis Zestos M, Stayer S, Kamiski E, Davies P, Andropoulos D. In: Andropoulos D, Mossad E, Gottlieb E, eds. Anesthesia for miscellaneous lesions. Anesthesia for Congenital Heart Disease. 4th ed. New Jersey: John Wiley & Sons, Inc.; 2023: 816-820.
