多発性嚢胞腎に合併した両側腎細胞癌の1例

Abstract

56歳男。30年前に多発性嚢胞腎を指摘され, 4年前より血液透析導入となっていた。今回, 外尿道口からの血性分泌物が出現し, 腹部造影CTで左腎上極の嚢胞壁肥厚を認め, 内部構造が不均一であり, 悪性病変を否定できず, 腹腔鏡下左腎摘出術を施行した。摘出腎の上極側嚢胞壁内に硬い腫瘤を認め, 病理学的診断はRenal cell carcinoma, clear cell carcinomaとpapillary carcinomaの混合型で, pT1a pN0M0G1 INFαv(-)であった。追加治療なしで経過観察していたが, 術後14ヵ月に再度外尿道口からの出血を認めた。内視鏡で膀胱・尿道に異常はなく, 腹部造影CTで右腎に腫瘤性病変は認めなかったが, 患者の希望により腹腔鏡下右腎摘除術を施行した。摘出標本は大小多彩な嚢胞を形成し, 嚢胞内に出血があったが, 腫瘤性病変は認めなかった。病理診断はRenal cell carcinoma, clear cell carcinomaで, pT1a pN0M0G2 INFβv(-)であった。再手術後16ヵ月経過し, 再発はない。

A 56-year-old Japanese man consulted a urologist because of urethral bleeding. He had been undergoing hemodialysis for the past 15 years due to polycystic kidney disease. Computed tomography revealed an irregular cyst wall in the left kidney. Since a neoplasm could not be ruled out, we removed the left kidney, by laparoscopic radical nephrectomy after obtaining the patient's consent. Histopathologic diagnosis was renal cell carcinoma. Fourteen months after the operation, urethral bleeding recurred. Further examination of the bladder and the urethra revealed no significant abnormalities. The patient insisted on right nephrectomy. Therefore, laparoscopic radical nephrectomy was performed. Histopathologic diagnosis was also renal cell carcinoma. Renal cell carcinoma in patients with end-stage renal disease is fairly common and is associated with acquired cystic kidney disease. However, renal cell carcinoma associated with polycystic kidney disease is extremely rare.