胸痛で発見され自然縮小した胸腺腫

Preoperative Spontaneous Regression of Thymoma

胸腺腫は悪性腫瘍の性格を有することから，徐々に増大するのが一般的である．胸腺腫自然縮小の報告は少なく，またその原因は不明であることが多い．われわれは胸痛を契機に発見され自然縮小をきたし，病理学的に腫瘍内血管の血栓塞栓像を認めた胸腺腫の1例を経験したので，文献的考察を加え報告する．

We report a case of preoperative spontaneous regression of thymoma in a 66-year-old woman who presented chest pain. Chest computed tomography revealed a well-defined tumor in the anterior mediastinum. The long axis of the tumor decreased from 25 to 18 mm during 1 month preoperatively. Video-assisted thoracoscopic thymothymectomy was performed for definitive diagnosis and treatment. Histopathologically, the tumor mainly comprised necrotic components with partially viable cells, and was diagnosed as a thymoma. The occlusion of the feeding artery by organized thrombus was found by pathology and it was considered to be the cause of coagulative necrosis.