小兒腎臟腫瘤以威廉氏瘤（Wilms’ tumor）最多，是相當惡性且組織構造極複雜的腫瘤。因發生率低，個人或一個研究單位能接觸的機會和經驗均不多，致使過去病理界，常把組織成分稍為複雜的小兒腎臟腫瘤都診斷為威廉式瘤。但自1965年美國成立國家威廉氏腫瘤研究中心（NWTS），集中所有小兒腎腫瘤病例而研究的結果有突破性的進展。除常見的一般威廉氏腫瘤（Wilms’ tumor）以外，已知在小孩腎腫瘤裡尚有分化度低而預後顯然不良的異分化威廉氏腫瘤（anaplastic Wilms’ tumor）以及比較稀罕但組織構造、細胞成份，臨床經過截然不同的兩種腫瘤所謂透明細胞肉瘤（clear cell sarcoma）及腎類橫紋肌瘤（rhabdoid tumor of the kidney）。鑑於本省對此兩種腫瘤尚缺詳細的報告。本研究介紹其臨床特徵（例如透明細胞肉瘤易發生骨骼轉移，類橫紋肌瘤的病人，原發或繼發的顱內腫瘤特高），病理組織學特點及其治療預後的情況，並對自驗病例三例（透明細胞瘤2例，一為3歲6個月，另一為1歲4個月男童，腎類橫紋肌瘤例3歲1一個月女童）的治療再發以致死亡經過，腫瘤眼觀及痛理組織學的特徵，特殊染色及免疫細胞化學反應結果作詳細報告。最後對一般威廉氏腫瘤，異分化威廉氏腫瘤，透明細胞肉瘤及腎類橫紋肌瘤，4種腫瘤的發生比率，易發年齡、性別比、左右比、主徵候、特殊徵候、腫瘤眼觀特點、邊緣浸潤狀況、組織學構造及細胞形狀特點、易轉移部位、及死亡率列表分析比較。

Both clear cell sarcoma of the kidney (CCSK) and rhabdoid tumor of the kidney (RTK) are rare and distinctive tumors mainly arising from the kidneys of children. Although they possess their own clinical behavior (the prognoses for these two tumors are worse than for the ordinary Wilm’s tumor) and their own particular pathological features, they have been classified for centuries merely as variants of Wilms’ tumor Study focused on these two tumor kinds has not been published in Taiwan before. Two cases of CCSK and one case of RTK, all filed as Wilms’ tumor, were found on review of 22 cases of renal tumors of childhood, accumulated in the pathology Department of the Taipei Medical College from 1962 to 1993. Their histochemical and immunocytochemical reactions as well as their histological features were studied; clinical courses, including prognoses, have been followed up. The morphologic specificities are stressed in the study, differences between the two tumors and other types of renal tumors of children are discussed; references are briefly reviewed.