Ultrasound (US) and CT scanning guided biopsy is the most commonly used method to diagnosis RCC. The sensitivity of biopsy for small masses (≤3 cm) is lower than for large masses [4]. Sensitivity is limited by false-negative results, which are due to a failure to properly target a small mass or the presence of impossible-to-differentiate benign from malignant cells due to insufficient cells, morphological overlap or cellular heterogeneity. Non diagnostic biopsy is not necessary benign, as repeated biopsy reveals malignancy diagnosis in the majority[5]. There is no radiologic criteria consistent with oncocytoma because of a lack of sensitivity and specificity [6]. MR-scanning and CT-scanning are not feasible diagnostic methodologies for oncocytoma because of the possibility of overlapping results from oncocytoma and RCC [7].