Management of small indeterminate renal tumours: is there a case for needle biopsy?

The incidence of RCC has increased over the last 50 years, largely due to enhanced detection of asymptomatic renal masses with the expanded use of imaging techniques such as ultrasonography and CT. Currently, more than a third of renal tumours are discovered incidentally [1]. The mainstay of diagnosis for renal tumours is cross-sectional imaging, but a group of solid and complex cystic lesions cannot be differentiated as definitely malignant or benign. In essence, many radiologists label such a renal mass as ‘indeterminate’ in contemporary practice, especially small lesions [2]. The dilemma for urologists then is how to manage this subgroup of patients.