術前に画像診断が困難であった後腹膜脂肪肉腫の2例

Abstract

症例1:58歳男.左上腹部腫瘤を自覚し近医を受診, 腹部CT検査上, 左腎に巨大腫瘤を認め, 紹介受診となった.画像所見より腫瘍径が巨大であり, 腎の圧排も高度であることから左腎摘除術を施行した.病理組織所見より高分化型(硬化型)脂肪肉腫と診断された.局所再発のリスクが高いと判断し, 術後補助化学療法を行った.有効性が高いとされているMEC療法(methotrexate, epirubicin, cisplatin)を選択し, 計2コース行った.術後3年経過し転移・再発は認められない.症例2:76歳男.糖尿病, 高血圧症で他院通院中, 超音波検査で左腎周囲に低エコー像を呈する腫瘤が発見され, 紹介受診となった.左副腎腫瘍の疑いで入院, 内分泌学的検査, 即効型インシュリンを用いた血糖管理を行った後, ホルモン非産生型副腎腫瘍の疑いで, 腫瘍摘出術を行った.腎血管の剥離・温存も困難と思われたため腎・副腎をen blocに切除した.病理組織診断は高分化型脂肪肉腫であった.軽快退院約1ヵ月後, 心疾患が悪化し, 現在通院困難となっている

We report two cases of retroperitoneal liposarcoma arisen from the perirenal fat tissue, which could not be diagnosed preoperatively. Case 1 is a 58-year-old male. He complained of left flank tumor. Computed tomography and magnetic resonance image showed a mass over 10 cm that contained fat components in the retroperitoneal space. The tumor was resected with left nephrectomy and histological examination revealed well differentiated liposarcoma. As adjuvant therapy, he received chemotherapy and 30 months has passed uneventfully. Case 2 is a 70-year-old male. Screening ultrasonography revealed incidental retroperitoneal tumor. With clinical diagnosis as non-functioning adrenal tumor, he received left nephrectomy. The pathological diagnosis was well differentiated liposarcoma, sclerosing type. No adjuvant therapy was performed. He has stopped visiting our clinic due to aggravation of heart disease. The characteristics of the images of the two cases were different despite the histological resemblance. This difference was considered to be due to the difference in the distribution of lipomatous tissue in each patient.