A 59-year-old man with history of renal cell carcinoma (RCC) presents for urological oncological evaluation after a community urologist discovers a 5.5 cm enhancing renal mass with a nephrometry score of 2+1+3+p+1=7p in his right solitary kidney. He had undergone a left nephrectomy 14 years earlier that revealed a Grade II clear cell RCC. The patient has excellent performance status and has minimal significant comorbidities. His glomerular filtration rate (GFR) was 47 mL/min/1.7m2 (CKD stage III).
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The malignant concordance rate (i.e., the chances that a mass is malignant if its contralateral counterpart was already proven to be cancer) between metachronous renal masses exceeds 95%.1 Similarly, synchronous bilateral renal masses also exhibit a high rate of pathologic concordance (one important caveat is that if one mass is benign, the chances that the other will be malignant appear to be over 30%).1, 2 Of 114 patients with bilateral metachranous renal masses treated at the Mayo Clinic for whom pathology was available, only 4.5% exhibited benign pathology in one kidney and a malignant tumor in the other.1 Interestingly, the patient described in the above case was found to have an oncocytoma upon partial nephrectomy, despite having a clear cell RCC in his contralateral kidney. The patient’s GFR was unchanged following partial nephrectomy.
The case was prepared by Alexander Kutikov, MD, of Fox Chase Cancer Center in Philadelphia.
1. Boorjian SA, Crispen PL, Lohse CM et al. The impact of temporal presentation on clinical and pathological outcomes for patients with sporadic bilateral renal masses. Eur Urol 2008;54:855-863.
2. Rothman J, Crispen PL, Wong YN et al. Pathologic concordance of sporadic synchronous bilateral renal masses. Urology 2008;72:138-142.