Predictors of benign histology in clinical T1a renal cell carcinoma tumors undergoing partial nephrectomy.

The anatomical characteristics of renal tumors have been classified using several systems. An association between tumor anatomical characteristics and postoperative histological diagnosis can be expected. The present study aimed to assess the rate of and predictive factors for benign histological findings for renal tumors diagnosed as T1a by preoperative imaging. From January 2000 through December 2010, 149 patients underwent partial nephrectomy (either open or laparoscopic) for T1a renal cell carcinoma. The frequency of benign histological findings was evaluated. Logistic regression analysis estimated the relative importance of predictive factors. The overall frequency of benign lesions was 8.1%. Multivariate analysis identified three statistically significant predictive factors for benign lesions: age, sex and exophytic tumor property (P = 0.0356, 0.0183 and 0.0330, respectively). The present findings suggest that exophytic tumors on preoperative imaging are more likely to be benign at histology after partial nephrectomy.