The incidental finding of a small renal mass poses a therapeutic dilemma. T
he traditional treatment of clinically important masses has been radical ne
phrectomy. Recently, nephron-sparing surgery has emerged as a viable altern
ative; and experimental minimally invasive percutaneous tissue ablation tec
hniques, including cryotherapy and radiofrequency ablation, are being evalu
ated. In this review, we discuss the dilemma posed by frequent renal imagin
g and the increased proportion of incidental tumors being detected, the lim
itations of needle biopsies for histologic diagnosis, nephron-conserving an
d minimally invasive surgery, and the possible merits of radiofrequency abl
ation and cryotherapy. We envision a defined role for minimally invasive pe
rcutaneous or extracorporeal ablation of small renal tumors. (C) 2001 by Ex
cerpta Medica, Inc.