Objective: The purpose of the study was to evaluate the management and interpersonal variability of Bosniak classification and demonstrate the present diagnostic dilemmas.
Material and methods: One-hundred and four patients with 113 complex renal cystic masses (26 Bosniak II,15 IIF,28 III and 44 IV) were included and analysed between April 1996 and May 2009.In total, 71 cystic masses were characterized by two radiologists in consensus initially as the first diagnosis (group 1), and then by a radiologist (group 2) and a urologist (group 3) independently in a blinded fashion.
Results: Only 11 patients (10.6%) were symptomatic (one Bosniak IIF, six III and four IV). Only one had renal cell carcinoma (RCC) on final histology, whereas the others (n = 10) had benign lesions. An overall pathological result was obtained in 71 masses (62.8%) (two Bosniak II, three IIF, 27 III and 39 IV). The overall incidence of RCC in surgically treated patients was 0%, 20%, 55.6% and 76.9% for each category, respectively. The interpersonal variability was significant among the three groups (especially in Bosniak II, IIF), and the overall category was changed in 54%, 20% and 41%, respectively (p < 0.001). After correlation with final histology and presumed benign character of Bosniak II/IIF lesions (all patients having reached 5-year follow-up) the differences were not significant.
Conclusion: It is challenging to minimize unnecessary surgical procedures in Bosniak category III. According to these results, it may make practical sense to group Bosniak II and IIF masses in one category.