腎臟惡性腫瘤以腎細胞癌及腎盂移形上皮細胞癌為主，腎臟肉瘤約只占所有腎臟惡性腫瘤的百分之一至三。而纖維肉瘤則只見於腎臟肉瘤的少數。我們報告一四十六歲男性病例因左側下背痛接受腹部超音波檢查而意外發現右側腎臟有一實質腫瘤，經進一步檢查後入院接受右側根除性腎臟切除手術。病理報告證實為一少見之腎臟纖維肉瘤。術後病人接受輔助性局部放射治療。於門診追蹤時發現已有肺臟、肝臟及脊椎骨骼多處轉移，於術後六個月因疾病死亡。腎臟纖維肉瘤雖較少見，但其預後卻是極差的，據文獻報告五年存活率少於百分之十。治療仍以根除性腎臟切除手術為主；化學治療或局部放射治療對存活率則無幫助。

Primary renal sarcomas of the kidney in adults are unusual, accounting for approximately 1% to 3% of all primary renal malignancies. Pathologically, leiomyosarcomas are the most frequent tumors of primary renal sarcomas, and fibrosarcomas of the kidney are rare. We report on a 46-yr-old male admitted to our hospital due to right side renal tumor. He received radical nephrectomy, and the histopathological report revealed primary fibrosarcoma of the right kidney. He received adjuvant radiotherapy with 5000 cGy due to invasion of the retroperitoneal muscle. Multiple organs metastases of lung, liver and bone developed 2 mo after nephrectomy. He died of the disease 6 mo after surgery. Prognoses of fibrosarcomas. Chemotherapy or radiotherapy is not helpful for survival. Herein, we present this case and review the literature.