Two-stage surgical resection of a massive primary posterior mediastinal dedifferentiated liposarcoma with bilateral thoracic extension: a case report.

Introduction and importance: Primary mediastinal dedifferentiated liposarcoma (DDLPS) is a rare and aggressive tumor, often diagnosed late due to nonspecific symptoms. The optimal surgical strategy for tumors with bilateral thoracic extension remains unclear. Case presentation: A 59-year-old woman presented with a 1-year history of exertional dyspnea. Chest computed tomography revealed a large posterior mediastinal mass extending into both thoracic cavities with compression of adjacent structures. A two-stage surgical approach was performed, with initial right thoracotomy followed by left thoracotomy for complete resection. Histopathology confirmed DDLPS with CDK4, MDM2, and S-100 positivity and MDM2 gene amplification. Clinical discussion: Complete surgical resection is the mainstay of treatment for mediastinal DDLPS. In cases with bilateral thoracic involvement, staged surgery may reduce operative risk and improve surgical safety compared to a single-stage approach. Conclusion: Staged surgical resection is a feasible and safe strategy for massive mediastinal DDLPS involving both thoracic cavities. Careful surgical planning is essential to achieve optimal outcomes.