Conservative management of small renal tumors.

With the widespread use of imaging modalities, incidentally discovered small renal cell carcinomas have increased. Some patients, however, are too old or weak due to various diseases to undergo surgery and other patients occasionally refuse surgery. To investigate the natural history of small renal cell carcinoma, we retrospectively reviewed patients with small renal tumors suggestive of carcinoma. We retrospectively reviewed 15 patients with contrast-enhancing renal masses less than 4.0 cm in diameter who were observed without treatment. The mean follow-up period was 38 months (range, 8-91). The average patient age was 67 years (range, 44-87). The initial average tumor diameter was 2.2 cm (range, 1.0-3.9). The average growth rate was 0.06 cm per year (range, -0.09-0.28). Only 4 tumors grew obviously during the follow-up period. Three tumors were removed surgically by radical nephrectomy, and all tumors were pathologically diagnosed as renal cell carcinoma. None of the patients developed metastases during the follow-up period or after surgery. Two patients died of other causes. Nonsurgical watchful waiting may be an acceptable treatment option for elderly or severely comorbid patients; however, it is not known whether this conservative management can be applied to young or otherwise healthy patients.