腎被膜脂肪肉腫の1例

Abstract

70歳男性.検診で顕微鏡的血尿を指摘され, 近医の腎超音波検査で右腎腫瘍が疑われ紹介入院となった.CTでは右腎下極の腎被膜部位に低吸収域の腫瘤を認め, MRIではT1強調で低信号, T2強調で不均一な低から高信号を示した.腎被膜腫瘍を疑い, 超音波ガイド下腫瘍生検を行い, well differentiated liposarcoma, sclerosing typeの診断で腎摘除術を施行した.腫瘍は弾性硬, 表面平滑で白色, 割面白色充実性で, 腎下極から上極まで腎被膜表面に沿って拡がっており, 病理所見ではfibrous tissueの中に小脂肪滴を含んだspindle cellが確認され, 生検結果と同様であった.また, 腎実質への浸潤を認めず, 腎周囲脂肪組織とはpseude capsuleで明瞭に分けられていた.術後は追加治療は行わず, その後14ヵ月経過にても再発は認めていない

A 70-year-old man was admitted to our hospital with microscopic hematuria. Abdominal echography, computed tomography and magnetic resonance imaging revealed renal capsular tumor, and radical nephrectomy was performed. The tumor was diagnosed histopathologically as liposarcoma (well differentiated type). This tumor did not invade the renal parenchyma but extended from the upper pole to the lower pole on the surface of the renal capsule. He has been alive without disease for 14 months after surgery.