ABSTRACT

“Renal cysts” is an important issue in urology practice due to the fact that a cyst can potentially be renal cystic cancer. Morton A. Bosniak introduced the first classification in 1986 for assessing the malignancy risk of renal cystic lesions. The Bosniak classification, which was revised in 2005, is used in routine radiology practice to identify lesions that need close observation or treatment. To precisely discriminate between each group in Bosniak classification, a more quantitative update was published in 2019. Researches based on these guidelines have demonstrated improved sensitivity and specificity in identifying malignant cysts, with no significant change in interobserver accuracy. This review aims to explain the Bosniak version 2019 classification system for the categorization of renal cystic lesions.