静脈血栓症を合併した心房中隔の脂肪腫様過形成の1例

Lipomatous Hypertrophy of Interatrial Septum in Patient with Venous Thrombus：Report of a Case

はじめに　心房中隔の脂肪腫様過形成（lipomatous hypertrophy of the interatrial septum：LHIS）は心房中隔に脂肪組織が蓄積する病変であり，被膜をもたない腫瘍様の増殖が特徴である．卵円窩レベルで厚さ2 cmを超える脂肪沈着がみられる場合にLHISと診断される1）．画像診断では欧米で成人の1％に認められるといわれている1～3）．症状を伴わないことがほとんどであり，剖検でみつかることが多かったが，画像診断の進歩で増加傾向にある．時に不整脈を合併することがある．また，大きなものでは大静脈閉塞や心不全をきたすことがある1，3，4）．

A 64-year-old female underwent a computed tomography （CT） examination of the chest because of pneumonia, which revealed lipomatous hypertrophy of the atrial septum. During medical treatment for pneumonia, venous thrombus of the superior vena cava occurred and then disappeared following apixaban administration. The patient refused surgery at that time, thus follow-up examinations include CT scans were conducted at the outpatient clinic. Two years later, the tumor became larger, and this time she accepted surgery. Under total cardiopulmonary bypass with beating heart a 5.0×3.5 cm tumor was resected. Because of its location very close to superior vena cava, upper area of the right atrium was augmented using a bovine pericardium. Following surgery, sick sinus syndrome developed and pacemaker implantation was performed. Thereafter, the patient had a smooth recovery and no recurrence is noted one year since.