Mesenchymal Tumors of the Mediastinum

Tumors of mesenchymal origin are relatively rare neoplasms that are most frequently found in the soft tissues of the extremities or in the abdomen. Primary sarcomas arising in the mediastinum are unusual entities, representing less than 10% of all adult mediastinal tumors and less than 2% of all soft tissue sarcomas. Approximately half of the primary mediastinal tumors of mesenchymal origin are estimated to be malignant. Mediastinal sarcomas may arise de novo or, rarely, in the context of somatic transformation of a mediastinal germ cell tumor (most commonly rhabdomyosarcomas and angiosarcomas). Overall, most soft tissue tumors reported in other anatomic sites have also been recognized in the mediastinum, resulting in a heterogeneous group of neoplasms. Among these, neurogenic tumors are by far the most common, accounting for approximately 20% of all adult and 35% of all pediatric mediastinal tumors. Liposarcomas, solitary fibrous tumors, and synovial sarcomas are other common mesenchymal lesions in this particular location. Due to the rarity and heterogeneity of mediastinal sarcomas, as well as the complex anatomy in this site, no consistent therapy approach has been outlined and the outlook for these patients remains poor. Surgical management remains the preferential treatment and completeness of surgical resection is an important factor determining survival in these patients.