Observation of small incidentally detected renal masses.

As more small (< 3.0 cm) incidentally detected renal cell carcinomas are being discovered in elderly patients, a reassessment of the management of these lesions has become an important issue. The use of partial nephrectomy in these small contained renal neoplasms is being more commonly performed, and the use of "watchful waiting" should also be considered as the initial management approach for some of these lesions. This latter approach is based on the experience gained by the observation of the growth rate and behavior of small incidentally detected solid renal masses that have been followed serially over a 2- to 8-year period. This report will review the available data on the growth rate and clinical behavior of small incidentally discovered renal neoplasms, show why a "watchful waiting" approach is reasonable in some of these cases, and outline which patients would benefit from this management approach.