胸部SMARCA4欠損腫瘍の1例

A case of SMARCA4-deficient thoracic sarcomatoid tumor

SMARCA4欠損は様々な臓器の悪性腫瘍に生じる遺伝子異常であり，予後不良因子とされている。今回，まれな胸部SMARCA4欠損腫瘍（SMARCA4-deficient thoracic sarcomatoid tumor）の1例を経験したので報告する。

A 40’s-years-old heavy smoker man with a dry cough and nocturnal dyspnea presented with a giant right hilar mass on a chest X-ray Image. The lesion was a giant sarcomatoid mass and poorly contrasted on contrast-enhanced CT. It invaded from the right hilum to the mediastinum （trachea and right main bronchi）. It had strong FDG uptake on ¹⁸F-FDG PET/CT and was accompanied by mediastinal lymph node metastasis. It was pathologically diagnosed by a biopsy as a SMARCA4-deficient thoracic sarcomatoid tumor （DTT）. The SMARCA4-DTT is a rare type of lung cancer, and aggressive and resistant to treatment compared with typical lung cancer. It was considered valuable to point out the possibility of SMARCA4-DTT in diagnostic imaging.