腹腔鏡下に切除した大網原発孤立性線維性腫瘍の1例

A case of solitary fibrous tumor originating from the greater omentum and resected by laparoscopic surgery

◆要旨：症例は47歳，女性．1型糖尿病の精査目的で撮影した腹部造影CTで右上腹部に2cm大の腹腔内腫瘤を指摘されたため，診断的治療として腹腔鏡下に切除術を施行した．腫瘤は大網原発で周囲臓器への浸潤はみられず，大網を含め腫瘤を切除した，摘出標本は24×28×20mmの弾性硬で，表面平滑な腫瘤であった．免疫染色にてSTAT6，CD34陽性，S100，desmin陰性であり，大網原発の孤立性線維性腫瘍（solitary fibrous tumor：以下，SFT）と診断した．術後3日目に軽快退院し，術後約1年間再発を認めていない．大網由来のSFTは報告も少なく極めて稀である．SFTの予後は一般に良好とされているが取り扱いはいまだ確立しておらず，組織学的に低悪性度であっても長期間の経過観察が必要とされ，さらなる症例の蓄積が望まれる．

　A 47-year-old woman was referred to our hospital because of type 1 diabetes mellitus, and abdominal enhanced computed tomography revealed a mass in the right upper side of her abdominal cavity. We performed laparoscopic tumorectomy including the greater omentum. The tumor was an elastic, hard mass with a smooth surface, and the size was 24 x 28 x 20 mm. Immunohistochemical staining showed the tumor was positive for STAT6 and CD34, and negative for S100 and desmin, so the patient was diagnosed with a solitary fibrous tumor（SFT）originating from the greater omentum. SFT originating from the greater omentum is extremely rare, and there are no clear guidelines for the treatment of SFT. Therefore, we should perform careful and long-term follow-up for such patients after operation, even if the histological findings show low mailgnancy.