精巣腫瘍と重複した乳頭状腎細胞癌

A papillary renal cell carcinoma developed in a patient with extensive testicular carcinoma after sixteen years disease free survival

43歳，男性。27歳時，左鎖骨下リンパ節腫大により受診，高位精巣摘出術後，精巣腫瘍と診断され（病期ⅢA），化学療法とリンパ節郭清術を施行した。16年後に腰背部痛と，左後腹膜腫瘤が出現し腫瘍摘出術を施行した。病理は左萎縮腎に発生した乳頭状腎細胞癌であった。近年，乳頭状腎細胞癌の中でも予後の悪い群が存在することが指摘されている。本症例は病理学的に予後悪性群の可能性があった。

A 49-year-old man with abdominal pain was referred to our hospital. He has a treatment history in our hospital because of stageⅢa testicular carcinoma 16 years ago. His CT revealed retroperitoneal soft tissue mass measured 6cm at its largest diameter associated with left atrophic kidney. Operative removal of the retroperitoneal mass clarified this tumor originating from his left atrophic kidney. Final pathological diagnosis was an eosinophilic variant of left papillary renal cell carcinoma（PRCC）. PRCC was generally thought to be a tumor with low malignant potential compared with conventional RCC. However,this case needs a very careful follow up because its eosinophilic variant has been reported recently to show poor prognosis.