Conservative management of incidental contrast-enhancing renal masses as safe alternative to invasive therapy.

OBJECTIVES: To describe small contrast-enhancing renal masses suggestive of cancer that were managed conservatively with watchful waiting and serial computed tomography scans. Advanced diagnostic imaging has led to the increased incidental detection of renal masses in patients whose multiple comorbid conditions preclude invasive management.
METHODS: A retrospective review was conducted of 29 consecutive patients with 29 incidentally detected asymptomatic renal masses less than 3.5 cm in diameter that were managed conservatively with watchful waiting (because of patient wishes or multiple comorbid conditions) and serial computed tomography scans.
RESULTS: The average patient age was 70 years (range 51 to 88), and the average duration of follow-up imaging was 32 months (range 10 to 89). The average number of follow-up computed tomography scans was 4.9 per patient (range 1 to 11). The average width of the renal masses at diagnosis was 1.83 cm (range 0.4 to 3.5), and the average change in size per year was 0.12 cm for all patients. Four patients underwent radical nephrectomy because of growth of the renal mass (n = 1) or patient wishes (n = 3). The histologic findings in 3 of these 4 patients were consistent with renal cell carcinoma. Two patients underwent radiofrequency ablation of the masses. At last follow-up, metastatic disease had not developed in any patient, and no patient had died of renal cell carcinoma. Two patients had died of other causes.
CONCLUSIONS: The results of our study showed that when comorbid conditions or patient wishes preclude invasive treatment, contrast-enhancing renal masses less than 3.5 cm wide that are suggestive of cancer can be safely managed with watchful waiting and serial computed tomography scans.