前縦隔脂肪肉腫の1例

A case of anterior mediastinal liposarcoma

前縦隔原発の脂肪肉腫はまれであり，さらにその中でも脱分化型の症例は非常にまれであるとされている。今回我々は，CT所見から前縦隔脂肪肉腫を診断しえた症例を経験したので，画像所見を中心に考察を加えて報告する。

A man in his 70s was incidentally detected with an anterior mediastinal tumor by cardiac ultrasound. A lobulated mass was pointed out in the anterior mediastinum on non-enhanced CT. The tumor also showed heterogeneous early and prolonged enhancement on dynamic CT. Additionally, a small amount of fat was retrospectively detected within the tumor. Thoracoscopic tumor resection was performed. The tumor was pathologically diagnosed with a dedifferentiated type of liposarcoma. Primary anterior mediastinal liposarcoma is rare. Therefore, the diagnosis is sometimes challenging. However, careful interpretation of fat can be a key to the correct diagnosis on CT and MRI imaging.