High rate of benign histology in radiologically suspect renal lesions.

Introduction: The objective of this study was to determine the incidence of benign renal lesions for clinically localised renal masses and the need for new diagnostic procedures to assess these lesions.

Material And Methods: This retrospective study included patients who underwent partial or radical nephrectomy between November 2010 and July 2013. All patients underwent a multiphase helical computed tomography (CT), which revealed suspected renal malignancy. The exclusion criteria were cystic tumours, biopsy before surgery, and disseminated and locally advanced disease. Lesions were defined as follows: small ≤ 4 cm, intermediate > 4 and ≤ 7 cm, and large > 7 cm.

Results: A total of 226 patients underwent radical or partial nephrectomy; of these 75 patients were excluded. In all, 151 had masses suspected of being malignant tumours on CT. The mean age was 62.9 years. The male: female ratio was 3:1. The distribution of small, intermediate and large lesions were 75 (49.7%), 47 (31.1%) and 29 (19.2%), respectively. Among the three types of lesions, 15 (20%), 5 (10.6%) and 3 (10.3%) were benign, respectively (p = 0.27). Partial nephrectomy was performed in 69.3% of patients with small tumours versus 23.4% of patients with intermediate tumours, p < 0.001.

Conclusion: Benign lesions were observed in 20% of small renal masses ≤ 4 cm even though CT revealed a suspect renal lesion. The need for new diagnostic approaches for clinically localised renal lesions is evident.

Funding: not relevant.

Trial Registration: not relevant.