腎臟平滑肌肉瘤為腎臟肉瘤中最常見的腫瘤，好發於四十歲，為一非常惡性且腫瘤本身能長到相當大的體積。由於罹患此腫瘤的病人預後極差且大多於病發兩年內死亡。我們報告一病例為十九歲男性病患，於手術切除腫瘤後，在本院四年半門診追蹤無任何腫瘤復發的跡象，並於文獻上做進一步探討。

The Literature is reviewed with reference to primary leiomyosarcoma of the kidney, and an additional case of this highly malignant tumor is reported. The tumor can grow to enormous size., with the highest incidence in the fourth decade. We report a case of a 19-year-old man with leiomyosarcoma of the kidney. He remains alive four and half years after surgery.