Triphasic abdominal imaging of bilateral renal masses
A 66-year-old black man initially presented for evaluation of incidentally detected, Stage I, cT1aN0M0, synchronous, bilateral, clinically localized tumors that were suspicious for renal cell carcinoma (RCC). He has a history of hypertension but is otherwise healthy, with normal renal function (creatinine 0.80 mg/dL; estimated glomerular filtration rate >60 mL/min/1.73m2).
Triphasic abdominal imaging (see figure) revealed a 2.4 x 2.1 cm solid enhancing lesion in the left mid pole (40 to 110 Hounsfield units) and a centrally cystic and peripherally enhancing 2.3 x2cm right upper pole lesion (28 to 66 Hounsfield units) that were new since his last imaging study performed in 2013. There was no evidence of regional lymphadenopathy or distant metastases.
Submit your diagnosis to see full explanation.
This case was prepared by Marc C. Smaldone, MD, MSH, Associate Professor of Urologic Oncology, Department of Surgery-Fox Chase Cancer Center, Temple University Health System, Philadelphia.
1. Rothman J, Crispen PL, Wong YN, et al. Pathologic concordance of sporadic synchronous bilateral renal masses. Urology. 2008;72: 138-142.
2. Campbell S, Uzzo RG, Allaf ME, et al. Renal Mass and Localized Renal Cancer: AUA Guideline. J Urol. 2017;198:520-529.
After extensive counseling, the patient elected to proceed with staged robotic partial nephrectomies revealing a right Stage I, pT1aN0M0, G2 clear cell RCC and a left Stage III, pT3aN0M0, Type II papillary renal cell carcinoma. He is currently undergoing surveillance with imaging per the NCCN guidelines and remains without evidence of recurrence.
Review of the literature demonstrates that in cases of bilateral sporadic localized synchronous renal masses, the malignant concordance rate ranges from 84-95%, with a histologic concordance rate of 93%. Benign concordance rates are much lower (ranging from 39% to 67%)1. This implies that a diagnosis of ipsilateral renal cell carcinoma is associated with contralateral RCC in the vast majority of patients, whereas ipsilateral benign pathology is associated with contralateral benign disease at a substantially lower rate. Histologic concordance is similarly high, meaning most cases of clear cell or papillary tumors ipsilaterally are concordant in the contralateral kidney.
The vast majority of early stage renal masses are found incidentally in asymptomatic patients. While active surveillance, percutaneous ablation, and surgical excision via partial or radical nephrectomy are all accepted management strategies, per the Renal Mass and Localized Renal Cancer: AUA Guideline that was published in 20172, staged nephron sparing surgery is the preferred treatment strategy in patients presenting with synchronous, sporadic, bilateral renal masses.