📌 Rhabdomyoma – Most common pediatric cardiac tumorBenign, hamartoma of cardiac myocytes. 70-95% associated with tuberous sclerosis complex (TSC1, TSC2). Multiple, intramural, regress spontaneously in 70%. May cause obstruction, arrhythmias (WPW).
📌 Fibroma – Second most commonSolitary, intramural, often left ventricle. No regression. May cause obstruction, VT. Associated with Gorlin syndrome (PTCH1 mutation). Surgical resection.
📌 Myxoma – Most common in adults, rare in childrenPedunculated, left atrium (75%), mobile. May cause obstruction (mitral valve) and systemic emboli. Carney complex (PRKAR1A) – multiple myxomas, spotty pigmentation, endocrine tumors.
📌 Other benign tumorsHemangioma, lipoma, teratoma, paraganglioma, mesothelial (AV node) – may cause heart block.
📌 MRI/CT – Characterize tissueMRI: rhabdomyoma isointense to myocardium. Fibroma: dark (calcification). Myxoma: heterogenous. CT: calcification in fibroma.
📌 Management – RhabdomyomaObservation with serial echo – spontaneous regression by age 2-4 years. mTOR inhibitors (everolimus, sirolimus) for symptomatic/obstructive tumors. Surgical resection if obstruction not regressing.
1️⃣ Asymptomatic rhabdomyoma (most common) ▪ Serial echocardiograms (every 6-12 months). Spontaneous regression by age 2-4 years. ▪ Screen for tuberous sclerosis: brain MRI, renal ultrasound, ophthalmology exam. ▪ Genetic counseling (TSC1/TSC2).
2️⃣ Symptomatic rhabdomyoma – Obstruction or arrhythmias ▪ mTOR inhibitors (everolimus, sirolimus) – first-line for obstructive tumors. ▪ Antiarrhythmics for WPW/VT (beta-blockers, flecainide, amiodarone). ▪ Surgical resection if refractory to medical therapy or life-threatening obstruction.
3️⃣ Fibroma – Solitary, no regression ▪ Symptomatic (obstruction, VT): surgical resection. ▪ Asymptomatic small fibroma: observe, but risk of VT. ▪ ICD if sustained VT or high-risk features.
4️⃣ Myxoma – Surgical excision ▪ Urgent surgery (risk of embolization). Complete resection with margin. ▪ Echo surveillance for recurrence (especially familial Carney complex). ▪ Treat embolic complications (anticoagulation).
6️⃣ Transition & long-term follow-up ▪ Tuberous sclerosis: lifelong multidisciplinary care (neurology, nephrology, dermatology). ▪ Cardiac MRI for scar/fibroma surveillance. ▪ Pregnancy: high-risk in tuberous sclerosis with rhabdomyoma (regression usually occurs, but arrhythmia risk).
❓ Reflex prompt 1: A 3-month-old with multiple cardiac masses on echo, hypopigmented macules on skin. Most likely diagnosis and associated syndrome? ✅ Answer: Rhabdomyomas with tuberous sclerosis complex. Genetic testing TSC1/TSC2.
❓ Reflex prompt 2: A 12-year-old with solitary left ventricular mass, calcified on echo, and history of basal cell carcinoma. Most likely diagnosis? ✅ Answer: Cardiac fibroma associated with Gorlin syndrome (PTCH1 mutation). Surgical resection if symptomatic.
❓ Reflex prompt 3: A 15-year-old with syncope, diastolic tumor plop, and left atrial mass on echo. Next step? ✅ Answer: Atrial myxoma – urgent surgical excision (risk of embolization).
❓ Reflex prompt 4: A neonate with rhabdomyoma causing RVOT obstruction, cyanosis. First-line medical therapy? ✅ Answer: mTOR inhibitor (everolimus, sirolimus) – reduces tumor size. Surgical resection if no response.
❓ Reflex prompt 5: A 10-year-old with tuberous sclerosis, rhabdomyoma, and WPW pattern. Antiarrhythmic choice? ✅ Answer: Beta-blocker or flecainide. Catheter ablation if medication failure.
❓ Reflex prompt 6: A 14-year-old with cardiac fibroma and sustained VT. Next step? ✅ Answer: Surgical resection if possible, ICD for secondary prevention.
📌 Tumors of the Heart – Core Concepts (Nelson 22e, Chapter 490)
1. Epidemiology: Rare in children. 90% are benign. Most common: rhabdomyoma (>50%), fibroma, myxoma, teratoma, hemangioma. 2. Rhabdomyoma – Most common pediatric tumor:
- Benign hamartoma of cardiac myocytes. 70-95% associated with tuberous sclerosis complex (TSC1, TSC2).
- Multiple, intramural, regress spontaneously in 70% by age 2-4 years.
- Complications: obstruction (RVOT, LVOT), arrhythmias (WPW, VT), heart failure.
- Treatment: observation if asymptomatic. mTOR inhibitors (everolimus, sirolimus) for symptomatic/obstructive tumors. Surgical resection if refractory. 3. Fibroma – Second most common:
- Solitary, intramural, often left ventricle. No regression.
- Associated with Gorlin syndrome (PTCH1 mutation, basal cell carcinomas).
- Complications: obstruction, ventricular tachycardia (VT). Surgical resection indicated for symptoms or VT. 4. Myxoma – Most common in adults:
- Pedunculated, left atrium (75%). Mobile, may cause obstruction (tumor plop) and systemic emboli.
- Carney complex (PRKAR1A mutation): multiple myxomas, spotty pigmentation, endocrine tumors.
- Treatment: urgent surgical excision (risk of embolization). Recurrence possible. 5. Other tumors: Hemangioma, lipoma (benign). Malignant: sarcoma, lymphoma (rare, poor prognosis). 6. Diagnosis:
- Echocardiogram (TTE) first-line: location, size, mobility.
- Cardiac MRI: tissue characterization (rhabdomyoma, fibroma, myxoma).
- ECG: WPW, VT, heart block.
- Genetic testing: TSC1/TSC2 (tuberous sclerosis), PRKAR1A (Carney), PTCH1 (Gorlin). 7. Treatment – General principles:
- Asymptomatic: observation.
- Symptomatic obstruction or arrhythmias: mTOR inhibitors (rhabdomyoma), surgical resection.
- Myxoma: urgent surgery.
- Malignant: surgery + chemo/radiation ± transplantation. 8. Prognosis: Rhabdomyoma spontaneously regresses. Fibroma stable or slow growth. Myxoma good after resection. Malignant poor. 💡 Clinical pearls:
➤ Any infant with cardiac rhabdomyoma should be evaluated for tuberous sclerosis (brain MRI, renal US, skin exam).
➤ WPW pattern in a child with tuberous sclerosis is likely due to rhabdomyoma; may regress with mTOR inhibitor.
➤ Tumor plop (diastolic sound) is classic for left atrial myxoma.
➤ Familial myxoma (Carney complex) requires lifelong echo surveillance for recurrence.
➤ Fibroma with VT: surgical resection or ICD.