肺転移病巣の自然消退をみた胞巣状軟部肉腫の1例

Alveolar Soft Part Sarcoma with Spontaneous Regression of Pulmonary Metastases

　抄録：症例は，14歳，男性．主訴は左大腿部腫瘤．腫瘤の増大により近医受診したところ，左大腿部腫瘍を指摘され，当科受診した．外来にて針生検術を施行した結果，胞巣状軟部肉腫と診断され，当科入院となった．入院後，術前治療として，三者併用療法を行い，その後，腫瘍広汎切除術を施行した．術後，全身化学療法を施行し，以後は外来にて経過観察とした．胸部CTの推移をみると，術後，転移病巣が認められるようになり，以後，転移巣は増加増大傾向を示したが，その後，減少縮小傾向に転じて，その傾向のまま現在まで至っている．胞巣状軟部肉腫の肺転移病巣の自然消退例は，われわれの渉猟し得た限りでは，本例が2例目であると思われる．その原因については未だ不明であり，一般的に他の悪性腫瘍の肺転移例においても，その自然消退後に再増悪が起こることがあることより，本例においても今後の慎重な経過観察が必要であると思われる．

　The patient was a 14-year-old male with a chief complaint of a lump in the left femoral region. The patient had consulted a local physician when it increased in size and was referred to our department. A needle biopsy specimen collected on an outpatient basis was diagnosed as alveolar soft part sarcoma, and the patient was admitted to our department. Combined chemotherapy (radio-hyperthermo-chemotherapy) was administered and followed by wide resection. Systemic chemotherapy was administered postoperatively, and the patient was monitored on an outpatient basis. Serial chest CT scans revealed metastatic lesions postoperatively, and for a while they continued to increase in number and size, but then steadily decreased in size and became radiographically denser. To the best of our knowledge, this is only the second case of spontaneous regression of metastatic pulmonary lesions from alveolar soft part sarcoma ever reported in Japan. The cause of this phenomenon is unknown, but because metastatic pulmonary lesions of other malignancies sometimes regress spontaneously and subsequently recur, the patient requires carefull follow-up.