Cardiac Magnetic Resonance Findings in a Rare Pediatric Case of Primary Cardiac Angiosarcoma

Description of Clinical Presentation: A 15-year-old girl presented with progressive shortness of breath, fatigue, and swelling of the upper extremities and face. Physical examination and imaging identified cardiac tamponade, pleural effusion, ascites, and signs of superior vena cava (SVC) syndrome. Echocardiography revealed a mediastinal mass infiltrating the right atrium and SVC. Pericardial drainage yielded hemorrhagic fluid with fibrin, sterile and without malignant cells. Despite drainage, recurrent pericardial effusion persisted, and clotting abnormalities developed.

Diagnostic Techniques and Their Most Important Findings: Cardiac magnetic resonance (CMR) was performed to further characterize the cardiac mass.
CMR demonstrated a cauliflower-shaped lesion infiltrating the right atrial wall, extending along the atrioventricular sulcus into the SVC. Balanced SSFP cine sequences confirmed a bulky, irregular mass with impaired right ventricular function. The lesion was predominantly isointense on T1-weighted imaging with areas of hyperintensity, and markedly hyperintense on T2-weighted STIR sequences, consistent with high fluid content and hemorrhage. Phase-sensitive inversion recovery (PSIR) sequences obtained 10 minutes post-contrast revealed heterogeneous late gadolinium enhancement with central null areas, consistent with necrosis and avascular regions.

These findings were highly suggestive of cardiac angiosarcoma. Histopathology from biopsy confirmed a poorly differentiated angiosarcoma. Further studies revealed pelvic metastases. Despite supportive measures, the patient rapidly deteriorated, developed cerebral hemorrhage, and passed away shortly after diagnosis.

Learning Points from this Case: Primary malignant cardiac tumors in children are extremely rare (< 0.03%), with sarcomas—particularly angiosarcomas—representing the most common histological type [^1,2]. Angiosarcomas typically arise in the right atrium and often present with hemorrhagic pericardial effusions and SVC obstruction [^3,4].
CMR provides essential non-invasive characterization, allowing assessment of anatomical extent, infiltrative behavior, and cardiac function. Angiosarcoma usually shows heterogeneous T1/T2 signal intensities, while late gadolinium enhancement frequently demonstrates necrotic areas [^3,5].
Despite its diagnostic value, prognosis remains poor, with reported median survival of less than one year in most series [^2,4,6]. Early clinical suspicion and advanced imaging are crucial to guide biopsy, multidisciplinary management, and potential multimodal therapies.

Image 1: Left. T1 Turbo spin echo with black blood prepulse showing the mass around the right atrial wall infiltrating the SVC and extending to the IVC. Iso intense with areas of hyperintensity. Middle: same position image in T2 STIR showing heterogeneous hyperintensity. Right: Balanced steady state free precession (BSSFP) cine image with cauliflower-like appearance.
Image 2: Left: PSIR sequence 10 minutes after contrast injection in four chambers view showing heterogeneous enhancement with a central area of null signal suggesting avascular region. Right: 4 chambers BSSFP cine sequence showing typical cauliflower-like appearance plus residual pericardial and pleural effusion.