Masas renales pequeñas: predictores de malignidad en una serie de 10 años / Small renal masses: analysis of 152 cases

ABSTRACT

Background: Small renal masses (SRM) are defined as complex organ-confined solid or cystic lesions < 4 cm. Up to 20% of these can be benign. A conservative management with active surveillance can be done in some patients. However, it is difficult to identify patients with a higher risk of malignancy. Aim: To characterize the clinical, radiological and histopathological aspects of patients with SRM, analyzing predictive factors for tumor aggressiveness. Material and Methods: Retrospective analysis of a cohort of patients undergoing partial or total nephrectomy for renal tumors between 2006 and 2016. All tumors of 4 cm or less were included. Four histological groups were defined benign, favorable, intermediate and unfavorable. Two categories of risk were also defined low and high. Preoperative clinical and radiological variables of these patients were analyzed. Results: Data of 152 patients were analyzed. Six percent had a benign histology, and the majority was of intermediate risk (74%). According to histological type, clear cell carcinoma was the most common type (74%). Three percent were benign angiomyolipomas. No malignancy predictive variable was identified. Conclusions: In these patients, the percentage of benign SRM was low. No variable that could predict the presence of a benign or malignant lesion in the definitive biopsy was identified.