気胸による肺虚脱時の胸部CTでのみ異常陰影を呈した前縦隔粘液型脂肪肉腫

Anterior Mediastinal Myxoid Liposarcoma Detected by Chest Computed Tomogram in the Patient with Pneumothorax

脂肪肉腫は軟部組織に発生することが多いが，縦隔発生はまれである1）．自然気胸発症時の胸部CTで，左肺が虚脱することにより異常陰影として発見された前縦隔粘液型脂肪肉腫を経験したので報告する．

A 57-year-old woman visited our hospital with left chest pain. Chest computed tomography （CT） scanning showed left pneumothorax with apical bullae and a nodular shadow in the left anterior mediastinum accidentally. However, a week later, we could not detect a mediastinal shadow on chest CT image after healing of left pneumothorax. Video assisted thoracoscopic surgery was scheduled in order to remove bullae and evaluate an anterior mediastinal lesion. The mediastinal lesion was tumorous and resected with around pericardial fat tissue. Pathological diagnosis was a myxoid liposarcoma of 15×10 mm in size without infiltration into the surrounding tissue. The postoperative course was uneventful without recurrence 6 months later.