Pediatric Cardiac Masses: Clinical Characteristics and Long-Term Outcomes From a Two-Decade Single-Center Experience

Technical Summary: Pediatric Cardiac Masses – Clinical Characteristics and Long-Term Outcomes

Problem Statement
Pediatric cardiac masses are rare, heterogeneous conditions encompassing a wide spectrum of benign and malignant lesions with variable clinical presentations and natural histories. While cardiac rhabdomyomas are recognized as the most common pediatric cardiac tumor and are strongly linked to tuberous sclerosis complex (TSC), long-term data covering the full spectrum of pediatric cardiac masses—including rare non-rhabdomyoma entities—remain limited. Existing evidence is largely derived from small retrospective series or isolated case reports, creating a gap in understanding the diverse clinical courses, management strategies, and long-term outcomes of these uncommon conditions in routine tertiary care.

Methodology
This study presents a retrospective, single-center analysis of 22 pediatric patients diagnosed with cardiac masses between January 2006 and January 2026 at Ege University Faculty of Medicine.

• Population: Patients under 18 years of age with echocardiographically confirmed cardiac masses.
• Data Collection: Demographic, clinical, imaging, treatment, and follow-up data were extracted from electronic medical records. Tumor behavior was classified as complete regression, partial regression, or no regression based on serial imaging.
• Imaging & Evaluation: Transthoracic echocardiography served as the primary diagnostic tool. Cardiac magnetic resonance imaging (MRI) and computed tomography (CT) were utilized selectively for tissue characterization and anatomical extent. Genetic testing for TSC1 and TSC2 was performed for suspected rhabdomyomas.
• Statistical Analysis: Continuous variables were reported as medians with interquartile ranges (IQR), and categorical variables as counts and percentages. Comparisons between cardiac rhabdomyomas and non-rhabdomyoma masses were conducted using nonparametric methods (Mann–Whitney U test and Fisher's exact test) due to the small sample size.

Key Results
The cohort consisted of 22 patients (13 male, 9 female), with a median age at diagnosis of 12 months (IQR 2–84).

• Tumor Subtypes: Cardiac rhabdomyomas were the predominant subtype (14 patients, 63.6%), followed by cardiac fibromas (4 patients, 18.2%). Rare entities included hydatid cysts, teratomas, metastatic involvement, and a single case of pericardial tufted angioma.
• Clinical Characteristics:
  • Rhabdomyomas: Diagnosed at a significantly younger age, frequently associated with antenatal detection (22.7% of total cohort), and strongly linked to TSC. They were predominantly multifocal (64.3% of rhabdomyoma cases) and associated with arrhythmias (42.9% of rhabdomyoma patients).
  • Non-Rhabdomyomas: Generally presented as solitary lesions and demonstrated greater pathological diversity.
• Arrhythmias: Rhythm disturbances occurred exclusively in the rhabdomyoma group (6 patients), ranging from ventricular ectopy to supraventricular/ventricular arrhythmias and Wolff–Parkinson–White patterns. No arrhythmias were observed in the non-rhabdomyoma group.
• Tumor Behavior & Regression: Spontaneous regression was a hallmark of rhabdomyomas. Complete regression was observed in 5 patients and partial regression in 6; 11 lesions remained stable. Regression was significantly more common in the rhabdomyoma group compared to non-rhabdomyomas.
• Management:
  • Conservative: Predominant strategy for asymptomatic or stable lesions.
  • Medical: mTOR inhibitors (sirolimus/everolimus) were used in 9 patients (40.9%), primarily for rhabdomyomas with significant burden or obstruction. Antiarrhythmic therapy was administered to 6 patients.
  • Surgical: Surgical intervention or diagnostic biopsy was required for 6 patients (27.3%), mostly due to hemodynamic compromise, diagnostic uncertainty, or refractory symptoms in non-rhabdomyoma cases.

Key Contributions

• Longitudinal Spectrum: The study provides a two-decade longitudinal view of a broad spectrum of pediatric cardiac masses, moving beyond the predominant focus on rhabdomyomas to include rare entities like pericardial tufted angioma, cardiac hydatid disease, and secondary involvement.
• Differentiation of Subtypes: It highlights distinct clinical phenotypes between rhabdomyomas (younger age, multifocal, TSC-associated, regressive, arrhythmogenic) and non-rhabdomyoma masses (solitary, heterogeneous, often requiring surgical or histopathological intervention).
• Multimodality Management: The paper details the integration of mTOR inhibitors, antiarrhythmics, and surgical approaches, illustrating how management is tailored to tumor subtype, anatomical location, and hemodynamic impact.
• Rare Case Documentation: It documents the clinical course and regression of a rare pericardial tufted angioma treated with sirolimus and propranolol, adding to the limited literature on targeted medical therapy for vascular tumors.

Significance and Claims
The authors claim that their two-decade single-center experience underscores the substantial clinical and biological heterogeneity of pediatric cardiac masses. The study emphasizes that clinical course is influenced not only by histopathological subtype but also by anatomical location, ventricular function, arrhythmia burden, and hemodynamic effects.

The paper asserts that while cardiac rhabdomyomas are the most common lesion, the management of pediatric cardiac masses requires individualized evaluation and longitudinal multidisciplinary follow-up. By presenting a diverse cohort that includes rare vascular, parasitic, and secondary lesions, the authors aim to contribute to the existing literature by offering insights into the varied presentation and real-world clinical management of these conditions in a tertiary pediatric cardiology setting. The study acknowledges limitations regarding its retrospective design, small sample size, and the lack of histopathological confirmation for all conservatively managed lesions, cautioning against broad generalizations while highlighting the value of their institutional experience.