*Result*: Defining new radiological patterns to improve classification of Bosniak III and IV cystic renal masses.
Title:
Defining new radiological patterns to improve classification of Bosniak III and IV cystic renal masses.
Authors:
Sebastià C; Hospital Clínic de Barcelona, Barcelona, Spain.; August Pi i Sunyer Biomedical Research Institute, Barcelona, Spain., Cabedo L; Hospital Clínic de Barcelona, Barcelona, Spain. cabedo@clinic.cat.; August Pi i Sunyer Biomedical Research Institute, Barcelona, Spain. cabedo@clinic.cat., Jiménez-Serrano S; Hospital Clínic de Barcelona, Barcelona, Spain., Alfambra H; Hospital Clínic de Barcelona, Barcelona, Spain., Corominas D; Hospital Clínic de Barcelona, Barcelona, Spain., Comas-Cufi M; University of Girona, Girona, Spain., Puig J; Hospital Clínic de Barcelona, Barcelona, Spain.; August Pi i Sunyer Biomedical Research Institute, Barcelona, Spain., Nicolau C; Hospital Clínic de Barcelona, Barcelona, Spain.; August Pi i Sunyer Biomedical Research Institute, Barcelona, Spain.
Source:
Abdominal radiology (New York) [Abdom Radiol (NY)] 2026 Feb; Vol. 51 (2), pp. 854-864. Date of Electronic Publication: 2025 Jul 02.
Publication Type:
Journal Article
Language:
English
Journal Info:
Publisher: Springer Country of Publication: United States NLM ID: 101674571 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 2366-0058 (Electronic) NLM ISO Abbreviation: Abdom Radiol (NY) Subsets: MEDLINE
Imprint Name(s):
Original Publication: [New York] : Springer, [2016]-
MeSH Terms:
Tomography, X-Ray Computed*/methods , Kidney Diseases, Cystic*/diagnostic imaging , Kidney Diseases, Cystic*/classification , Kidney Diseases, Cystic*/pathology , Kidney Neoplasms*/diagnostic imaging , Kidney Neoplasms*/pathology , Kidney Neoplasms*/classification, Humans ; Retrospective Studies ; Middle Aged ; Male ; Female ; Adult ; Aged ; Diagnosis, Differential ; Aged, 80 and over
References:
Bosniak M. A. (1986). The current radiological approach to renal cysts. Radiology, 158(1), 1–10. https://doi.org/10.1148/radiology.158.1.3510019. (PMID: 10.1148/radiology.158.1.35100193510019)
Israel, G. M., & Bosniak, M. A. (2005). An update of the Bosniak renal cyst classification system. Urology, 66(3), 484–488. https://doi.org/10.1016/j.urology.2005.04.003. (PMID: 10.1016/j.urology.2005.04.00316140062)
Silverman, S. G., Pedrosa, I., Ellis, J. H., Hindman, N. M., Schieda, N., Smith, A. D., Remer, E. M., Shinagare, A. B., Curci, N. E., Raman, S. S., Wells, S. A., Kaffenberger, S. D., Wang, Z. J., Chandarana, H., & Davenport, M. S. (2019). Bosniak Classification of Cystic Renal Masses, Version 2019: An Update Proposal and Needs Assessment. Radiology, 292(2), 475–488. https://doi.org/10.1148/radiol.2019182646. (PMID: 10.1148/radiol.2019182646312106166677285)
Park, M. Y., Park, K. J., Kim, M. H., & Kim, J. K. (2021). Bosniak Classification of Cystic Renal Masses Version 2019: Comparison with Version 2005 for Class Distribution, Diagnostic Performance, and Interreader Agreement Using CT and MRI. AJR. American journal of roentgenology, 217(6), 1367–1376. https://doi.org/10.2214/AJR.21.25796.
Zhang, Q., Dai, X., & Li, W. (2022). Diagnostic performance of the Bosniak classification, version 2019 for cystic renal masses: A systematic review and meta-analysis. Frontiers in oncology, 12, 931592. https://doi.org/10.3389/fonc.2022.931592. (PMID: 10.3389/fonc.2022.931592363305039623069)
McGrath, T. A., Bai, X., Kamaya, A., Park, K. J., Park, M. Y., Tse, J. R., Wang, H., McInnes, M. D. F., & Schieda, N. (2023). Proportion of malignancy in Bosniak classification of cystic renal masses version 2019 (v2019) classes: systematic review and meta-analysis. European radiology, 33(2), 1307–1317. https://doi.org/10.1007/s00330-022-09102-w. (PMID: 10.1007/s00330-022-09102-w35999371)
Dana, J., Gauvin, S., Zhang, M., Lotero, J., Cassim, C., Artho, G., Bhatnagar, S. R., Tanguay, S., & Reinhold, C. (2023). CT-based Bosniak classification of cystic renal lesions: is version 2019 an improvement on version 2005?. European radiology, 33(2), 1297–1306. https://doi.org/10.1007/s00330-022-09082-x. (PMID: 10.1007/s00330-022-09082-x36048207)
Pruthi, D. K., Liu, Q., Kirkpatrick, I. D. C., Gelfond, J., & Drachenberg, D. E. (2019). Long-Term Surveillance of Complex Cystic Renal Masses and Heterogeneity of Bosniak 3 Lesions. The Journal of urology, 10.1097/JU.0000000000000144. Advance online publication. https://doi.org/10.1097/JU.0000000000000144. (PMID: 10.1097/JU.0000000000000144315499357487279)
Chandrasekar, T., Ahmad, A. E., Fadaak, K., Jhaveri, K., Bhatt, J. R., Jewett, M. A. S., & Finelli, A. (2018). Natural History of Complex Renal Cysts: Clinical Evidence Supporting Active Surveillance. The Journal of urology, 199(3), 633–640. https://doi.org/10.1016/j.juro.2017.09.078. (PMID: 10.1016/j.juro.2017.09.07828941915)
Sebastià, C., Corominas, D., Musquera, M., Paño, B., Ajami, T., & Nicolau, C. (2020). Active surveillance of small renal masses. Insights into imaging, 11(1), 63. https://doi.org/10.1186/s13244-020-00853-y. (PMID: 10.1186/s13244-020-00853-y323721947200970)
Wood, C. G., 3rd, Stromberg, L. J., 3rd, Harmath, C. B., Horowitz, J. M., Feng, C., Hammond, N. A., Casalino, D. D., Goodhartz, L. A., Miller, F. H., & Nikolaidis, P. (2015). CT and MR imaging for evaluation of cystic renal lesions and diseases. Radiographics: a review publication of the Radiological Society of North America, Inc, 35(1), 125–141. https://doi.org/10.1148/rg.351130016. (PMID: 10.1148/rg.35113001625590393)
Shen, J., & Zou, Y. (2024). Diagnostic value of contrast-enhanced CT in clear cell renal cell carcinoma: a systematic review and meta-analysis. BMC urology, 24(1), 189. https://doi.org/10.1186/s12894-024-01574-w. (PMID: 10.1186/s12894-024-01574-w3921888611368016)
Dilauro, M., Quon, M., McInnes, M. D., Vakili, M., Chung, A., Flood, T. A., & Schieda, N. (2016). Comparison of Contrast-Enhanced Multiphase Renal Protocol CT Versus MRI for Diagnosis of Papillary Renal Cell Carcinoma. AJR. American journal of roentgenology, 206(2), 319–325. https://doi.org/10.2214/AJR.15.14932. (PMID: 10.2214/AJR.15.1493226797358)
Pitra, T., Pivovarcikova, K., Alaghehbandan, R., Bartos Vesela, A., Tupy, R., Hora, M., & Hes, O. (2022). A Comprehensive Commentary on the Multilocular Cystic Renal Neoplasm of Low Malignant Potential: A Urologist’s Perspective. Cancers, 14(3), 831. https://doi.org/10.3390/cancers14030831. (PMID: 10.3390/cancers14030831351590988834316)
Elbaset, M. A., Ashour, R., Elgamal, M., Elbatta, A., Ghobrial, F. K., Abouelkheir, R. T., Mosbah, A., & Osman, Y. (2023). The efficacy of the new Bosniak classification v.2019 in benign lesions prediction within the higher Bosniak cysts classes. Urologic oncology, 41(10), 434.e1–434.e7. https://doi.org/10.1016/j.urolonc.2023.06.007. (PMID: 10.1016/j.urolonc.2023.06.00737574368)
Shampain, K. L., Shankar, P. R., Troost, J. P., Galantowicz, M. L., Pampati, R. A., Schoenheit, T. R., Shlensky, D. A., Barkmeier, D., Curci, N. E., Kaza, R. K., Khalatbari, S., & Davenport, M. S. (2022). Interrater Agreement of Bosniak Classification Version 2019 and Version 2005 for Cystic Renal Masses at CT and MRI. Radiology, 302(2), 357–366. https://doi.org/10.1148/radiol.2021210853. (PMID: 10.1148/radiol.202121085334726535)
Bai, X., Sun, S. M., Xu, W., Kang, H. H., Li, L., Jin, Y. Q., Gong, Q. G., Liang, G. C., Liu, H. Y., Liu, L. L., Chen, S. L., Wang, Q. R., Wu, P., Guo, A. T., Huang, Q. B., Zhang, X. J., Ye, H. Y., & Wang, H. Y. (2020). MRI-based Bosniak Classification of Cystic Renal Masses, Version 2019: Interobserver Agreement, Impact of Readers’ Experience, and Diagnostic Performance. Radiology, 297(3), 597–605. https://doi.org/10.1148/radiol.2020200478. (PMID: 10.1148/radiol.202020047832960726)
Richard, P. O., Violette, P. D., Bhindi, B., Breau, R. H., Gratton, M., Jewett, M. A. S., Kapoor, A., Pouliot, F., Leveridge, M., So, A. I., Whelan, T. F., Rendon, R. A., Tanguay, S., & Finelli, A. (2023). 2023 UPDATE - Canadian Urological Association guideline: Management of cystic renal lesions Prior to original publication (March 2017), this guideline underwent review by the CUA Guidelines Committee, CUA members at large, and the CUA Executive Board. The 2023 updates were app roved by the CUA Guidelines Committee and CUA Executive Board. Canadian Urological Association journal = Journal de l’Association des urologues du Canada, 17(6), 162–174. https://doi.org/10.5489/cuaj.8389.
https://uroweb.org/guidelines/renal-cell-carcinoma.
Lee, R. A., Uzzo, R. G., Anaokar, J., Thomas, A., Wei, S., Ristau, B. T., McIntosh,A., Lee, M., Chen, D. Y. T., Greenberg, R. E., Viterbo, R., Smaldone, M. C., Correa,A., Schober, J., Ginsburg, K., Bukavina, L., Magee, D., Uzzo, N., Parkansky, P., Ruth,K.,… Kutikov, A. (2023). Pathological and Clinical Outcomes in a Large Surveillance and Intervention Cohort of Radiographically Cystic Renal Masses. The Journal of urology,209(4), 686–693. https://doi.org/10.1097/JU.0000000000003158.
Möller, K., Jenssen, C., Correas, J. M., Safai Zadeh, E., Bertolotto, M., Ignee, A., Dong, Y., Cantisani, V., & Dietrich, C. F. (2023). CEUS Bosniak Classification-Time for Differentiation and Change in Renal Cyst Surveillance. Cancers, 15(19), 4709. https://doi.org/10.3390/cancers15194709. (PMID: 10.3390/cancers151947093783540310571952)
Lucocq, J., Morgan, L., Rathod, K., Szewczyk-Bieda, M., & Nabi, G. (2023). Validation of the updated Bosniak classification (2019) in pathologically confirmed CT-categorised cysts. Scottish medical journal, 369330231221235. Advance online publication. https://doi.org/10.1177/00369330231221235.
Perri, D., Mazzoleni, F., Pacchetti, A., Rossini, M., Morini, E., Berti, L., Buizza, C., Besana, U., & Bozzini, G. (2023). Pathological report and prognostic meaning of Bosniak IV cysts: results from a contemporary cohort. Central European journal of urology, 76(3), 186–189. https://doi.org/10.5173/ceju.2023.083R. (PMID: 10.5173/ceju.2023.083R3804578710690387)
Israel, G. M., & Bosniak, M. A. (2005). An update of the Bosniak renal cyst classification system. Urology, 66(3), 484–488. https://doi.org/10.1016/j.urology.2005.04.003. (PMID: 10.1016/j.urology.2005.04.00316140062)
Silverman, S. G., Pedrosa, I., Ellis, J. H., Hindman, N. M., Schieda, N., Smith, A. D., Remer, E. M., Shinagare, A. B., Curci, N. E., Raman, S. S., Wells, S. A., Kaffenberger, S. D., Wang, Z. J., Chandarana, H., & Davenport, M. S. (2019). Bosniak Classification of Cystic Renal Masses, Version 2019: An Update Proposal and Needs Assessment. Radiology, 292(2), 475–488. https://doi.org/10.1148/radiol.2019182646. (PMID: 10.1148/radiol.2019182646312106166677285)
Park, M. Y., Park, K. J., Kim, M. H., & Kim, J. K. (2021). Bosniak Classification of Cystic Renal Masses Version 2019: Comparison with Version 2005 for Class Distribution, Diagnostic Performance, and Interreader Agreement Using CT and MRI. AJR. American journal of roentgenology, 217(6), 1367–1376. https://doi.org/10.2214/AJR.21.25796.
Zhang, Q., Dai, X., & Li, W. (2022). Diagnostic performance of the Bosniak classification, version 2019 for cystic renal masses: A systematic review and meta-analysis. Frontiers in oncology, 12, 931592. https://doi.org/10.3389/fonc.2022.931592. (PMID: 10.3389/fonc.2022.931592363305039623069)
McGrath, T. A., Bai, X., Kamaya, A., Park, K. J., Park, M. Y., Tse, J. R., Wang, H., McInnes, M. D. F., & Schieda, N. (2023). Proportion of malignancy in Bosniak classification of cystic renal masses version 2019 (v2019) classes: systematic review and meta-analysis. European radiology, 33(2), 1307–1317. https://doi.org/10.1007/s00330-022-09102-w. (PMID: 10.1007/s00330-022-09102-w35999371)
Dana, J., Gauvin, S., Zhang, M., Lotero, J., Cassim, C., Artho, G., Bhatnagar, S. R., Tanguay, S., & Reinhold, C. (2023). CT-based Bosniak classification of cystic renal lesions: is version 2019 an improvement on version 2005?. European radiology, 33(2), 1297–1306. https://doi.org/10.1007/s00330-022-09082-x. (PMID: 10.1007/s00330-022-09082-x36048207)
Pruthi, D. K., Liu, Q., Kirkpatrick, I. D. C., Gelfond, J., & Drachenberg, D. E. (2019). Long-Term Surveillance of Complex Cystic Renal Masses and Heterogeneity of Bosniak 3 Lesions. The Journal of urology, 10.1097/JU.0000000000000144. Advance online publication. https://doi.org/10.1097/JU.0000000000000144. (PMID: 10.1097/JU.0000000000000144315499357487279)
Chandrasekar, T., Ahmad, A. E., Fadaak, K., Jhaveri, K., Bhatt, J. R., Jewett, M. A. S., & Finelli, A. (2018). Natural History of Complex Renal Cysts: Clinical Evidence Supporting Active Surveillance. The Journal of urology, 199(3), 633–640. https://doi.org/10.1016/j.juro.2017.09.078. (PMID: 10.1016/j.juro.2017.09.07828941915)
Sebastià, C., Corominas, D., Musquera, M., Paño, B., Ajami, T., & Nicolau, C. (2020). Active surveillance of small renal masses. Insights into imaging, 11(1), 63. https://doi.org/10.1186/s13244-020-00853-y. (PMID: 10.1186/s13244-020-00853-y323721947200970)
Wood, C. G., 3rd, Stromberg, L. J., 3rd, Harmath, C. B., Horowitz, J. M., Feng, C., Hammond, N. A., Casalino, D. D., Goodhartz, L. A., Miller, F. H., & Nikolaidis, P. (2015). CT and MR imaging for evaluation of cystic renal lesions and diseases. Radiographics: a review publication of the Radiological Society of North America, Inc, 35(1), 125–141. https://doi.org/10.1148/rg.351130016. (PMID: 10.1148/rg.35113001625590393)
Shen, J., & Zou, Y. (2024). Diagnostic value of contrast-enhanced CT in clear cell renal cell carcinoma: a systematic review and meta-analysis. BMC urology, 24(1), 189. https://doi.org/10.1186/s12894-024-01574-w. (PMID: 10.1186/s12894-024-01574-w3921888611368016)
Dilauro, M., Quon, M., McInnes, M. D., Vakili, M., Chung, A., Flood, T. A., & Schieda, N. (2016). Comparison of Contrast-Enhanced Multiphase Renal Protocol CT Versus MRI for Diagnosis of Papillary Renal Cell Carcinoma. AJR. American journal of roentgenology, 206(2), 319–325. https://doi.org/10.2214/AJR.15.14932. (PMID: 10.2214/AJR.15.1493226797358)
Pitra, T., Pivovarcikova, K., Alaghehbandan, R., Bartos Vesela, A., Tupy, R., Hora, M., & Hes, O. (2022). A Comprehensive Commentary on the Multilocular Cystic Renal Neoplasm of Low Malignant Potential: A Urologist’s Perspective. Cancers, 14(3), 831. https://doi.org/10.3390/cancers14030831. (PMID: 10.3390/cancers14030831351590988834316)
Elbaset, M. A., Ashour, R., Elgamal, M., Elbatta, A., Ghobrial, F. K., Abouelkheir, R. T., Mosbah, A., & Osman, Y. (2023). The efficacy of the new Bosniak classification v.2019 in benign lesions prediction within the higher Bosniak cysts classes. Urologic oncology, 41(10), 434.e1–434.e7. https://doi.org/10.1016/j.urolonc.2023.06.007. (PMID: 10.1016/j.urolonc.2023.06.00737574368)
Shampain, K. L., Shankar, P. R., Troost, J. P., Galantowicz, M. L., Pampati, R. A., Schoenheit, T. R., Shlensky, D. A., Barkmeier, D., Curci, N. E., Kaza, R. K., Khalatbari, S., & Davenport, M. S. (2022). Interrater Agreement of Bosniak Classification Version 2019 and Version 2005 for Cystic Renal Masses at CT and MRI. Radiology, 302(2), 357–366. https://doi.org/10.1148/radiol.2021210853. (PMID: 10.1148/radiol.202121085334726535)
Bai, X., Sun, S. M., Xu, W., Kang, H. H., Li, L., Jin, Y. Q., Gong, Q. G., Liang, G. C., Liu, H. Y., Liu, L. L., Chen, S. L., Wang, Q. R., Wu, P., Guo, A. T., Huang, Q. B., Zhang, X. J., Ye, H. Y., & Wang, H. Y. (2020). MRI-based Bosniak Classification of Cystic Renal Masses, Version 2019: Interobserver Agreement, Impact of Readers’ Experience, and Diagnostic Performance. Radiology, 297(3), 597–605. https://doi.org/10.1148/radiol.2020200478. (PMID: 10.1148/radiol.202020047832960726)
Richard, P. O., Violette, P. D., Bhindi, B., Breau, R. H., Gratton, M., Jewett, M. A. S., Kapoor, A., Pouliot, F., Leveridge, M., So, A. I., Whelan, T. F., Rendon, R. A., Tanguay, S., & Finelli, A. (2023). 2023 UPDATE - Canadian Urological Association guideline: Management of cystic renal lesions Prior to original publication (March 2017), this guideline underwent review by the CUA Guidelines Committee, CUA members at large, and the CUA Executive Board. The 2023 updates were app roved by the CUA Guidelines Committee and CUA Executive Board. Canadian Urological Association journal = Journal de l’Association des urologues du Canada, 17(6), 162–174. https://doi.org/10.5489/cuaj.8389.
https://uroweb.org/guidelines/renal-cell-carcinoma.
Lee, R. A., Uzzo, R. G., Anaokar, J., Thomas, A., Wei, S., Ristau, B. T., McIntosh,A., Lee, M., Chen, D. Y. T., Greenberg, R. E., Viterbo, R., Smaldone, M. C., Correa,A., Schober, J., Ginsburg, K., Bukavina, L., Magee, D., Uzzo, N., Parkansky, P., Ruth,K.,… Kutikov, A. (2023). Pathological and Clinical Outcomes in a Large Surveillance and Intervention Cohort of Radiographically Cystic Renal Masses. The Journal of urology,209(4), 686–693. https://doi.org/10.1097/JU.0000000000003158.
Möller, K., Jenssen, C., Correas, J. M., Safai Zadeh, E., Bertolotto, M., Ignee, A., Dong, Y., Cantisani, V., & Dietrich, C. F. (2023). CEUS Bosniak Classification-Time for Differentiation and Change in Renal Cyst Surveillance. Cancers, 15(19), 4709. https://doi.org/10.3390/cancers15194709. (PMID: 10.3390/cancers151947093783540310571952)
Lucocq, J., Morgan, L., Rathod, K., Szewczyk-Bieda, M., & Nabi, G. (2023). Validation of the updated Bosniak classification (2019) in pathologically confirmed CT-categorised cysts. Scottish medical journal, 369330231221235. Advance online publication. https://doi.org/10.1177/00369330231221235.
Perri, D., Mazzoleni, F., Pacchetti, A., Rossini, M., Morini, E., Berti, L., Buizza, C., Besana, U., & Bozzini, G. (2023). Pathological report and prognostic meaning of Bosniak IV cysts: results from a contemporary cohort. Central European journal of urology, 76(3), 186–189. https://doi.org/10.5173/ceju.2023.083R. (PMID: 10.5173/ceju.2023.083R3804578710690387)
Contributed Indexing:
Keywords: Bosniak cyst; Computed tomography; Follow-up; Malignancy; Renal cell carcinoma
Entry Date(s):
Date Created: 20250702 Date Completed: 20260223 Latest Revision: 20260226
Update Code:
20260226
PubMed Central ID:
PMC12929308
DOI:
10.1007/s00261-025-05092-7
PMID:
40601023
Database:
MEDLINE
*Further Information*
*Objectives: We aimed to compare Bosniak III and IV cystic renal masses (CRM) using Bosniak classification version 2005 (BC-v2005) versus BC-v2019 and analyze radiological findings and patterns of benignity and malignancy.
Methods: We retrospectively reviewed all Bosniak III-IV CRMs using BC-v2005 at our center with four-phase CT confirmed pathology, between January 2014 and June 2019. Two radiologists independently re-evaluated each lesion using both BCs, including findings of benignity and malignancy. Bosniak III-IV CRMs were classified in four radiological patterns: inflammatory (CRM-IP), cystic nephroma (CRM-CNP), papillary (CRM-PP), and clear cell (CRM-CCP). Characteristics of patterns were compared.
Results: Out of 97 patients, 57 Bosniak III-IV CRMs met the inclusion criteria. Twenty-four (42.10%) lesions were reclassified as solid tumours using BC-v2019. Any lesion was downgraded to IIF or lower. Nine (15.78%) lesions were upgraded to Bosniak III-IV CRMs by BC-v2019, despite benign lesions. The presence of acute-angle nodules was the only statistically significant sign of malignancy (p < 0.01). All benign lesions, not considered solid, were included in the two patterns of benignity, characterized by thickened septa and/or wall and without acute-angle nodules. All malignant CRMs presented two patterns of malignancy, proposed as acute-angle nodules. All clear cell carcinomas presented with hyperenhancing acute-angle nodules in the arterial phase. Pattern classification was better for BC-v2005 and BC-v2029, differentiating benign and malignant CRM.
Conclusion: The proposed four radiological patterns improved performance than BC-v2019 in classifying benign lesions (CRM-IP and CRM-CNP) and malignant ones (CRM-PP and CRM-CCP), with wall and septa thickening and acute-angle nodules as relevant biomarkers.
(© 2025. The Author(s).)*
*Declarations. Competing interests: The authors declare no competing interests.*