A huge mediastinal, well-differentiated liposarcoma with heterogenous smooth muscle differentiation: a case report.

: Liposarcoma is one of the most common mesenchymal tumors, although liposarcomas that occur in the mediastinum are uncommon. We recently encountered a case of mediastinal well-differentiated liposarcoma with secondary myxoid changes and smooth muscle differentiation in a 54-year-old man. The patient reported a 20-day history of chest pain, and thorax computed tomography revealed a large and multilobulated mass with heterogeneous density in the posterior and anterior mediastinum, which extended to the right hemithorax. Resection was performed and a pathological analysis subsequently confirmed a diagnosis of well-differentiated liposarcoma. The patient experienced recurrence at 15 months after the surgery and subsequently died of heart failure.