Pathological heterogeneity in sporadic synchronous renal tumors: Is the histological concordance predictable?

Abstract Objective To evaluate the pathological concordance rate of multiple synchronous renal masses (MSRM) presumed to be sporadic and to analyze predictive factors of concordance. Material and methods We identified from our institutional database patients with sporadic MSRM treated at our center between January 2000 and December 2015. All tumors were reviewed by a dedicated uropathologist. Pathological concordance rate was analyzed regarding clinical characteristics and preoperative imaging. Results We included 112 patients: 50 had unilateral synchronous renal masses and 62 bilateral synchronous renal masses. A total of 291 tumors were analyzed, with an average of 2.6 tumors per patient. Overall, the malignant concordance rate was 91.6%, the pathological concordance rate was 67.3% and the grade concordance rate was 62.5%. In univariate analysis, predictive factors of histological concordance were bilateral synchronous renal masses (odds ratio [OR] = 3.39; 95% CI: 1.06–10.8; P = 0.04), age P = 0.02) and ≥3 lesions (OR = 2.41; 95% CI: 1.03–5.68; P = 0.04). In multivariate analysis, age P = 0.02). Conclusions The histological concordance rate of MSRM is low. Age at diagnosis