Safe Resection of a Giant Mediastinal Liposarcoma with Severe Cardiac Compression

INTRODUCTION: Dedifferentiated liposarcomas of the mediastinum are exceedingly rare, and surgical resection is the primary treatment of choice. Mediastinal mass syndrome (MMS) is an oncological emergency characterized by compression or invasion of the heart, great vessels, or trachea by a large mediastinal tumor, particularly during the induction of anesthesia. We report a case of a giant dedifferentiated liposarcoma in the anterior mediastinum, surgically resected due to severe cardiac compression and presenting as an oncological emergency. CASE PRESENTATION: A 70-year-old male presented with palpitations, generalized fatigue, and chest tightness. Chest radiography revealed an enlarged mediastinal shadow, prompting referral to our hospital. CT revealed a rapidly growing, giant anterior mediastinal tumor measuring 22 × 14.5 × 8.5 cm. The mass caused significant cardiac compression and extended into the pleural cavity. A CT-guided percutaneous biopsy confirmed a dedifferentiated liposarcoma. Given the patient's presentation of tachycardia and relatively low blood pressure secondary to the large tumor, a semi-urgent surgical resection was planned. Surgical resection was performed with veno-arterial extracorporeal membrane oxygenation (VA-ECMO) on standby, anticipating potential hemodynamic decompensation during the induction of general anesthesia and surgery. Remarkably, the patient's hemodynamics remained stable throughout the induction of general anesthesia, without requiring VA-ECMO support. A clamshell incision allowed for complete tumor resection, including a portion of the pericardium. Postoperatively, the patient recovered uneventfully, except for transient paroxysmal atrial fibrillation and heart failure. The final pathological diagnosis confirmed dedifferentiated liposarcoma, with tumor cells affecting the pericardial and anterior chest wall surgical margins. The patient received postoperative radiation therapy and adjuvant chemotherapy and has remained free of recurrence for 1 year after surgery. CONCLUSIONS: We successfully performed semi-urgent surgery in a patient with a rapidly growing, giant anterior mediastinal mass causing severe cardiac compression, with VA-ECMO on standby. As MMS constitutes an oncologic emergency, careful assessment of subjective symptoms and imaging findings is required to determine the need for preparing or initiating extracorporeal life support.