Bosniak Category IIF and III Cystic Renal Lesions: Outcomes and Associations

Published Online:https://doi.org/10.1148/radiol.11110888

A history of primary renal malignancy, coexisting Bosniak category IV cystic renal lesion and/or solid renal mass (common in patients with resected Bosniak category IIF cystic renal lesions), and multiplicity of Bosniak category III cystic renal lesions were all associated with an increased risk of malignancy in Bosniak IIF and III cystic renal lesions.

Purpose

To evaluate clinical outcomes, pathologic subtypes, metastatic disease rate, and clinical features associated with malignancy in Bosniak category IIF and III cystic renal lesions.

Materials and Methods

This retrospective study was institutional review board approved and HIPAA compliant. Informed consent was waived. Radiology and hospital information systems were searched for Bosniak IIF and Bosniak III lesions in computed tomographic (CT) reports from January 1, 1994 to August 31, 2009. Patients 18 years and older with unenhanced and contrast material–enhanced CT results and with lesions either surgically resected or with 1 year or more of surveillance were included. Data recorded were history of renal cell carcinoma, number of renal lesions, presence of a coexistent solid renal mass, surgical pathologic findings, and presence of metastatic disease from a renal malignancy. Sixty-two patients with 69 Bosniak IIF lesions and 131 patients with 144 Bosniak III lesions were identified. Proportions from independent groups were compared by using the Fisher exact test; continuous variables were compared by using a two-tailed two-sample t test or a Wilcoxon two-sample test.

Results

The malignancy rate of resected Bosniak IIF lesions was 25% (four of 16) and that for Bosniak III lesions was 54% (58 of 107) (P = .03). Thirteen percent (nine of 69) of Bosniak IIF lesions progressed at follow-up, and 50% (four of eight) of these resected cysts were malignant. History of primary renal malignancy, coexisting Bosniak category IV lesion and/or solid renal mass, and multiplicity of Bosniak III lesions were each associated with an increased malignancy rate in Bosniak III lesions. No patients developed locally advanced or metastatic disease from a Bosniak IIF or III lesion.

Conclusion

Although the malignancy rate in surgically excised Bosniak IIF and Bosniak III cystic renal lesions was 25% and 54%, respectively, in our study, the malignancy rate was higher in patients with a history of primary renal malignancy or coexisting Bosniak IV lesion and/or solid renal neoplasm.

© RSNA, 2011

References

  • 1 Bosniak MA. The current radiological approach to renal cysts. Radiology 1986;158(1):1–10. LinkGoogle Scholar
  • 2 Smith ND, Campbell SC. Evaluation of the renal mass. In: Kursh EDUlchaker JC. eds. Office urology: the clinician’s guide. Totowa, NJ: Humana, 2001; 145–163. CrossrefGoogle Scholar
  • 3 Cloix P, Martin X, Pangaud C, et al.. Surgical management of complex renal cysts: a series of 32 cases. J Urol 1996;156(1):28–30. Crossref, MedlineGoogle Scholar
  • 4 Wilson TE, Doelle EA, Cohan RH, Wojno K, Korobkin M. Cystic renal masses: a reevaluation of the usefulness of the Bosniak classification system. Acad Radiol 1996;3(7):564–570. Crossref, MedlineGoogle Scholar
  • 5 Aronson S, Frazier HA, Baluch JD, Hartman DS, Christenson PJ. Cystic renal masses: usefulness of the Bosniak classification. Urol Radiol 1991;13(2):83–90. Crossref, MedlineGoogle Scholar
  • 6 Siegel CL, McFarland EG, Brink JA, Fisher AJ, Humphrey P, Heiken JP. CT of cystic renal masses: analysis of diagnostic performance and interobserver variation. AJR Am J Roentgenol 1997;169(3):813–818. Crossref, MedlineGoogle Scholar
  • 7 O’Malley RL, Godoy G, Hecht EM, Stifelman MD, Taneja SS. Bosniak category IIF designation and surgery for complex renal cysts. J Urol 2009;182(3):1091–1095. Crossref, MedlineGoogle Scholar
  • 8 Curry NS, Cochran ST, Bissada NK. Cystic renal masses: accurate Bosniak classification requires adequate renal CT. AJR Am J Roentgenol 2000;175(2):339–342. Crossref, MedlineGoogle Scholar
  • 9 Israel GM, Bosniak MA. Follow-up CT of moderately complex cystic lesions of the kidney (Bosniak category IIF). AJR Am J Roentgenol 2003;181(3):627–633. Crossref, MedlineGoogle Scholar
  • 10 Spaliviero M, Herts BR, Magi-Galluzzi C, et al.. Laparoscopic partial nephrectomy for cystic masses. J Urol 2005;174(2):614–619. Crossref, MedlineGoogle Scholar
  • 11 Warren KS, McFarlane J. The Bosniak classification of renal cystic masses. BJU Int 2005;95(7):939–942. Crossref, MedlineGoogle Scholar
  • 12 Graumann O, Osther SS, Osther PJ. Characterization of complex renal cysts: a critical evaluation of the Bosniak classification. Scand J Urol Nephrol 2011;45(2):84–90. Crossref, MedlineGoogle Scholar
  • 13 Hartman DS, Davis CJ, Johns T, Goldman SM. Cystic renal cell carcinoma. Urology 1986;28(2):145–153. Crossref, MedlineGoogle Scholar
  • 14 Eble JNSauter GEpstein JISesterhenn IA. eds. Pathology and genetics of tumours of the urinary system and male genital organs. Lyon, France: IARC Press, 2004. Google Scholar
  • 15 Han KR, Janzen NK, McWhorter VC, et al.. Cystic renal cell carcinoma: biology and clinical behavior. Urol Oncol 2004;22(5):410–414. Crossref, MedlineGoogle Scholar
  • 16 Silverman SG, Mortele KJ, Tuncali K, Jinzaki M, Cibas ES. Hyperattenuating renal masses: etiologies, pathogenesis, and imaging evaluation. RadioGraphics 2007;27(4):1131–1143. LinkGoogle Scholar
  • 17 Vikram R, Ng CS, Tamboli P, et al.. Papillary renal cell carcinoma: radiologic-pathologic correlation and spectrum of disease. RadioGraphics 2009;29(3):741–754. LinkGoogle Scholar
  • 18 Brinker DA, Amin MB, de Peralta-Venturina M, Reuter V, Chan DY, Epstein JI. Extensively necrotic cystic renal cell carcinoma: a clinicopathologic study with comparison to other cystic and necrotic renal cancers. Am J Surg Pathol 2000;24(7):988–995. Crossref, MedlineGoogle Scholar
  • 19 Berland LL, Silverman SG, Gore RM, et al.. Managing incidental findings on abdominal CT: white paper of the ACR incidental findings committee. J Am Coll Radiol 2010;7(10):754–773. Crossref, MedlineGoogle Scholar
  • 20 Benjaminov O, Atri M, O’Malley M, Lobo K, Tomlinson G. Enhancing component on CT to predict malignancy in cystic renal masses and interobserver agreement of different CT features. AJR Am J Roentgenol 2006;186(3):665–672. Crossref, MedlineGoogle Scholar

Article History

Received May 5, 2011; revision requested June 14; revision received August 5; accepted August 10; final version accepted August 23.
Published online: Jan 2012
Published in print: Jan 2012