前縦隔原発脱分化型脂肪肉腫の1例

Dedifferentiated Liposarcoma of the Anterior Mediastinum；Report of a Case

はじめに　脂肪肉腫は四肢，後腹膜に好発する軟部組織腫瘍で，縦隔発生はまれである．脱分化型脂肪肉腫は組織亜型の中でも頻度が低く，予後不良である．われわれは前縦隔に発生した脱分化型脂肪肉腫の一切除例を経験したので，文献的考察を加え報告する．

A 69-year-old man was pointed out the anterior mediastinal mass on chest computed tomography （CT）. Since the thymoma was suspected, thymectomy was performed through median sternotomy. The tumor was encapsulated and did not directly invade adjacent organs. The tumor was 8.3×5.3×8.2 cm in size. Histological examination of the resected specimen showed a large mucinous component and a small fibrous component, both containing many atypical spindle cells and multinuclear giant cells, and fat cells and atypical lipoblasts observed in a small part of the specimen. The postoperative pathological diagnosis was dedifferentiated liposarcoma. No relapse is observed without adjuvant therapy at 1 year after surgery.