The detection of incidental renal tumours has dramatically increased over the last twenty years as a result of widespread ultrasound and CT scanning for various other conditions. Renal cancer is now an incidental diagnosis in over 50% of cases1. Survival rates have dramatically improved as a result of early surgical intervention (radical or partial nephrectomy)2. However, despite advances in radiology, benign renal lesions may be indeterminate from renal cancer. We report our incidence of patients undergoing nephrectomy for clinically diagnosed renal cancer but with subsequent benign pathology.
A 12 year retrospective study was performed on all 913 patients who underwent nephrectomy at Tallaght hospital (2000-2012). Five hundred and ninety three patients had a nephrectomy for presumed renal cancer of whom 575 patients had confirmed neoplasm by pathology. Forty-two patients had benign pathology (radiological false positive rate 7.1%). The average lesion size was 5.9 cms and the most frequent diagnoses included oncocytoma (69%) and angiomyolipoma (17%). The incidental detection of small renal masses (SRM) has particularly increased and management is controversial. Other studies demonstrate false-positive diagnostic rates for cancer between 10-30%3-5. Renal biopsy can be useful in small and indeterminate lesions but is not diagnostic in up to 22%. Contrast enhanced ultrasound (CEUS) and blood oxygenated level dependent MRI (BOLD MRI) show promise in differentiating benign and malignant renal masses but presently there is no definitive test radiological or otherwise for renal cell malignancy6,7. The current significant overtreatment of incidentally detected benign renal lesions is a serious concern but should be considered in the overall context of the now excellent prognosis for incidentally detected renal cancer.
SM Inder, L Smyth, NF Davis, J Thornhill
Department of Urology, AMNCH, Tallaght, Dublin 24
- Jayson M, Sanders H. Increased incidence of serendipitously discovered renal cell carcinoma. Urology 1998 Feb;51:203-5)
- Bosetti C, Bertuccio P, Chatenoud L, Negri E, La Vecchia C, Levi F. Trends in mortality from urological cancers in Europe, 1970-2008. Eur Urol 2011; 60-1-15
- Xiong Yh, Zhang ZL, Li YH, Liu ZW, Hou GL, Liu Q, Yun JP, Zhang XQ, Zhou FJ. Benign pathological findings in 303 Chinese patients undergoing surgery for presumed localised renal cell carcinoma. Int J Urol, 2010 Jun;17:517-521
- Lindkvist Pedersen C, Winck-Flyvholm L, Dahl C, Azawi NH. High rate of benign histology in radiologically suspect renal lesions. Dan Med J 2014 Oct;61:A4932
- Lee Sh, Park SU, Rha KH, Choi YD, Hong SJ, Yang SC, Mah SY, Chung BH. Trends in the incidence of benign pathological lesions at partial nephrectomy for presumed renal cells carcinoma in renal masses on preoperative computed tomography imaging: a single institute experience with 290 consecutive patients. Int JUrol.2010 Jun;17:512-6.
- Atri M, Tabatabaeifar L, Jang HJ, Finelli A, Moshonov H, Jewett M. Accuracy of Contrast-enhanced US for differentiating benign from malignant solid small renal masses. Radiology, Apr 2015,28:140907
- Wu GY, Suo ST, Lu Q, Zhang J, Zhu JR. The value of Blood Oxygenated Level Dependent (BOLD) MR imaging in differentiation of renal solid mass and grading of renal cell carcinoma (RCC): analysis based on largest cross sectional area versus the entire whole tumour. PLoS One, Apr 15;10.