Clinical Report: Extensive Cardiac Myxosarcoma Involving Both Atria

Overview

Primary cardiac tumors are rare, with malignant types such as myxosarcomas being extremely uncommon and associated with poor prognosis. This report details a 23-year-old male with a giant myxosarcoma affecting both atria, initially misdiagnosed as myxoma, who experienced rapid postoperative recurrence and succumbed to complications within a short survival period.

Background

Primary cardiac tumors occur infrequently, with benign tumors comprising 75% and malignant tumors 25% of cases. Among malignant cardiac tumors, sarcomas predominate, and myxosarcomas are a rare histological subtype. These tumors often mimic benign myxomas in imaging and pathology, leading to diagnostic challenges and insufficient surgical resection. Malignant cardiac tumors generally have poor outcomes due to aggressive behavior and high recurrence rates.

Data Highlights

Key Findings

• Primary cardiac tumors are rare; 75% benign and 25% malignant, with sarcomas representing 75% of malignant cases.
• Cardiac myxosarcomas are extremely rare and often misdiagnosed as myxomas preoperatively due to similar imaging and histological features.
• The reported case involved a young male with a giant myxosarcoma affecting both atria, causing obstructive symptoms and hemodynamic compromise.
• Imaging revealed large hyperechoic masses in both atria, with obstruction of ventricular inflow tracts and associated complications such as pericardial effusion and right heart insufficiency.
• Despite surgical resection, the tumor exhibited highly malignant behavior with rapid postoperative recurrence leading to vena cava obstruction, heart failure, and multiple organ failure.

Clinical Implications

Clinicians should maintain a high index of suspicion for malignant cardiac tumors like myxosarcoma in patients presenting with cardiac masses, especially when imaging reveals bilateral atrial involvement and rapid symptom progression. Accurate preoperative diagnosis is critical to guide surgical planning and improve resection completeness. Due to aggressive tumor biology, close postoperative monitoring for recurrence is essential, and multidisciplinary management may be warranted.

Conclusion

Cardiac myxosarcomas, though rare, pose significant diagnostic and therapeutic challenges due to their aggressive nature and resemblance to benign myxomas. Early recognition and comprehensive treatment strategies are vital to improve patient outcomes.

References

1. Primary cardiac tumors incidence and prognosis -- Clinical Case Report 2025