Cystic renal masses: A reevaluation of the usefulness of the Bosniak classification system

CUA guideline on the management of cystic renal lesions

“…They may also demonstrate contrast-enhanced septa (usually multiple) that are usually irregular, thickened, and/or calcified. A significant proportion of these cysts are thought to be malignant (mean of 54%; Table 2), 6,[11][12][13]15, with larger lesions being more likely to be malignant than smaller ones. 47,49 Bosniak category IV Category IV cysts may have similar characteristics to those classified as category III.…”

“…11,12,15,[23][24][25][26][27]31,33,34,39,40,42,43,47,51,59 However, the literature is thought to overestimate the true risk of malignancy among category II cysts, as the majority were managed conservatively or had features that made them too complex to be categorized as a Bosniak II cyst. 6,12,26,29,31,32,35,38,59 Importantly, even if malignant, most behave in a relatively benign fashion.…”

CT-guided biopsy of indeterminate renal cystic masses (Bosniak 3 and 2F): accuracy and impact on clinical management

“…His category-1 lesions are comprised of benign cysts with no need for further followup, his category 4 lesions cystic neoplasms should be managed by surgery, his category 2 lesions benign but complex cysts call for relatively frequent follow-up, whereas exploration is advocated for category 3. However, even with category 2 lesions other authors encountered a rate of malignancy of up to 80% [2]. In category 3 lesions an incidence of malignancies of 30-100% is reported by different investigators [2,3,4].…”

“…However, even with category 2 lesions other authors encountered a rate of malignancy of up to 80% [2]. In category 3 lesions an incidence of malignancies of 30-100% is reported by different investigators [2,3,4]. This potentially high error rate in lesions slated for follow-up and also a considerable interobserver variability when using the Bosniak classification for characterization of cystic renal lesions pose a management dilemma for the treating physician [5,6,7].…”

Bayesian Classifier for Predicting Malignant Renal Cysts on MDCT: Early Clinical Experience

“…In addition, previous studies have shown its potentially limited validity for identifying malignant renal cysts because a considerable number of pathologically proven malignant cysts were classified as category 2 in the CT interpretations [4][5][6][7][8][9][10][11][12][13][14].…”