特異な形態を呈した胸腔内脂肪腫の1胸腔鏡手術例

Thoracoscopic surgery for a pericardial lipoma with a rare morphology : A case report

◆要旨：患者は77歳，男性．1か月前より続く左胸壁の痛みを主訴に受診した．左第6，7肋間付近に紫斑を伴う弾性軟，大きさ2cm程度の腫瘤を触知した．CT検査では，心膜より連続する脂肪組織が肋間より胸壁を経由し皮下へ膨隆している所見を認めた．この腫瘤に対し，胸腔鏡下切除術を施行した．術中所見では，画像所見同様，心臓周囲の脂肪組織が一部膨隆して肋間に引き込まれており，ヘルニア様の状態であった．脂肪組織と心膜，また胸壁組織のそれぞれの境界は不明瞭であり，鋭的に剝離を行い切除した．病理組織検査では，脂肪腫の診断であり，存在形態より傍心膜脂肪腫の胸壁陥頓，癒着であった可能性が高いと考える．稀少な形態を示す縦隔内脂肪腫であったが，これに対して胸腔鏡下で切除しえたため，若干の文献的考察を加えて報告する．

A 77-year-old man presented with a chief complaint of pain in the left chest that had persisted for a month. A soft elastic mass approximately 2 cm in size with purpura was palpable near the region between the left 6th and 7th ribs. A computed tomography scan revealed that adipose tissue continuous with the pericardium had swelled between the ribs and to the subcutaneous layers via the chest wall. Thoracoscopic surgery was performed, and intraoperative findings were the same as the imaging findings, showing partial swelling of pericardial adipose tissue between the ribs, with a hernia-like condition. The boundaries between the adipose tissue and pericardium as well as chest wall, were indistinct. Thus, removal was performed through sharp dissection. Lipoma was diagnosed based on histopathological examination. Here we report a case of mediastinal lipoma with a rare morphology, which was thorascopically removed.