The Importance of Lesion Size as an Indicator of Malignancy in Bosniak Category 3 Cystic Renal Masses

Abstract

Objective: To evaluate the relationship between lesion size and malignancy rates in surgically removed Bosniak 3 renal cysts.

Material and Methods: Patients who underwent radical / partial nephrectomy for cystic renal mass between January 2010 and December 2018 were retrospectively analyzed. Fifty two patients who were diagnosed as Bosniak 3 renal cyst in preoperative computed tomography (CT) and / or Magnetic Resonance Imaging (MRI) images were included in the study. ROC Curve analysis was performed among Bosniak 3 lesions and tumor size cut-off value predicting malignancy was found. Patients with tumor size below and above this value were compared in terms of patient characteristics and histopathological data.

Results: The mean patient age was 54.2 ± 13.1 years and the mean follow-up period was 39.9 ± 25.2 months. The malignancy rate for all Bosniak 3 lesions was 63.5%. Male gender and low tumor size were correlated with malignancy in both univariate and multivariate analysis in comparison of patients with malignant and benign pathology. In the ROC Curve analysis, the cut-off value of the cyst, which predicted malignancy, was 45 mm (AUC = 0.735, p = 0.005). Patients were divided into two groups according to tumor size ≤45 mm (Group 1) and > 45 mm (Group 2). The malignancy rate was 77.8% and 48% in Group 1 and 2, respectively (p = 0.026, OR: 0.26, CI: 0.079-0.875).

Conclusion: In Bosniak 3 renal cysts, low tumor size was found to be associated with malignancy.

Keywords

• Renal cysts,osniak classification,lesion size,malignancy

Bosniak Kategori 3 Kistik Kitlelerde Malignite Göstergesi Olarak Lezyon Boyutunun Önemi

Abstract

Amaç: Cerrahi olarak çıkarılan Bosniak 3 renal kistlerde lezyon boyutunun malignite ile ilişkisini değerlendirmek

Gereç ve Yöntemler: Ocak 2010 ve Aralık 2018 tarihleri arasında kistik renal kitle nedeniyle radikal/parsiyel nefrektomi yapılan hastalar retrospektif olarak incelendi. Preoperatif bilgisayarlı tomografi (BT) ve/veya Magnetik Resonans Görüntüleme (MRG) görüntülerinde Bosniak 3 olarak değerlendirilen 52 hasta çalışmaya dahil edildi. Bosniak 3 lezyonlar arasında ROC Curve analizi yapılarak maligniteyi öngören tümör boyutu cut-off değeri bulundu. Bu değerin altında ve üstünde tümör boyutuna sahip hastalar hasta karakteristikleri ve histopatolojik veriler açısından karşılaştırıldı.

Bulgular: Ortalama hasta yaşı 54.2±13.1 ve ortalama takip süresi 39.9±25.2 aydı. Tüm Bosniak 3 lezyonlar için malignite oranı 63.5% olarak gözlendi. Malign ve benign patolojisi olan hastaların hasta karakteristiklerine göre karşılaştırılmasında erkek cinsiyet ve düşük tümör boyutu hem tek değişkenli hem de çok değişkenli analizde malignite ile ilişkili olarak olarak bulundu. ROC Curve analizinde maligniteyi öngören kist boyutu cut-off değeri 45 mm saptandı (AUC=0.735, p=0.005). Tümör boyutu ≤45 mm (Grup 1) ve >45 mm (Grup 2)  olmasına göre hastalar iki gruba ayrıldı. Malignite oranı iki grupta sırasıyla 77.8% ve 48% olarak bulundu (p=0.026, OR:0.26, CI:0.079-0.875).

Sonuç: Bosniak 3 böbrek kistlerinde düşük tümör boyutu malignite göstergesi olarak bulunmuştur.

Keywords

• böbrek kistleri,Bosniak sınıflaması,lezyon boyutu,malignite

References

1. 1. Ascenti G, Mazziotti S, Zimbaro G, et al Complex cystic renal masses: characterization with contrast-enhanced US. Radiology 2007;243: 158-165 DOI: 10.1148/radiol.2431051924
2. 2. Bosniak MA. The current radiological approach to renal cysts. Radiology 1986;158:1-10. DOI: 10.1148/radiology.158.1.3510019
3. 3. Bosniak MA. Diagnosis and management of patients with complicated cystic lesions of the kidney. AJR Am J Roentgenol. 1997;169:819–21.
4. 4. Bosniak MA. Problems in the radiologic diagnosis of renal parenchymal tumors. Urol Clin North Am. 1993;20:217–30.
5. 5. Israel GM, Bosniak MA. Follow-up CT of moderately complex cystic lesions of the kidney (Bosniak category IIF). AJR Am J Roentgenol. 2003;181:627–33.
6. 6. Schoots IG, Zaccai K, Hunink MG, Verhagen PCMS. Bosniak classification for cmplex renal cyts reevaluated: a systematic review. J Urol 2017;198:12-21. DOI: 10.1016/j.juro.2016.09.160
7. 7. Balci NC, Semelka RC, Patt RH, et al. Complex renal cysts: Findings on MR imaging. AJR Am J Roentgenol 1999;172:1495-500. https://doi.org/10.2214/ajr.172.6.10350279
8. 8. Israel GM, Hindman N, Bosniak MA. Evaluation of cystic renal masses: Comparison of CT and MR imaging by using the Bosniak classification system. Radiology 2004;231:365-71. https://doi.org/10.1148/ radiol.2312031025

9. 9. Defortescu G, Cornu JN, Bejar S, et al. Diagnostic performance of contrast-enhanced ultrasonography and magnetic resonance imaging for the assessment of complex renal cysts: A prospective study. Int J Urol 2017;24:184-9. DOI: 10.1111/iju.13289
10. 10. Park, J. J., Chang Jeong, B., Kim, C. K. et al.: Postoperative Outcome of Cystic Renal Cell Carcinoma Defined on Preoperative Imaging: A Retrospective Study. J Urol, 2016
11. 11. Jhaveri, K., Gupta, P., Elmi, A. et al.: Cystic Renal Cell Carcinomas: Do They Grow, Metastasize, or Recur? American Journal of Roentgenology, 2013;201: W292
12. 12. Cloix PX, Martin X, Pangaud C, et al. Surgical management of complex renal cysts: A series of 32 cases. J Urol 1996;156:28-30. https://doi.org/10.1016/S0022-5347(01)65928-7
13. 13. Smith AD, Remer EM, Cox KL, et al. Bosniak category IIF and III cystic renal lesions: Outcomes and associations. Radiology 2012;262:152-60. https://doi.org/10.1148/radiol.11110888
14. 14. El-Mokadem I, Budak M, Pillai S, et al. .Progression, interobserver agreement, and malignancy rate in complex renal cysts ( ≥ Bosniak category IIF). Urol Oncol. 2014;32(1):24.e21-7. doi: 10.1016/j.urolonc.2012.08.018.
15. 15. Lam CJ, Kapoor A. The true malignancy risk of Bosniak III cystic renal lesions: Active surveillance or surgical resection? Can Urol Assoc J 2018;12(6):E276-80. http://dx.doi.org/10.5489/cuaj.4960
16. 16. Volpe A, Mattar K, Finelli A, et al. Contemporary results of percutaneous biopsy of 100 small renal masses: a single center experience. J Urol 2008;180:2333–2337.
17. 17. Posielski NM, Bui A, Wells SA, et al. Risk Factors for Complications and Nondiagnostic Results following 1,155 Consecutive Percutaneous Core Renal Mass Biopsies. J Urol 2019;5:101097JU0000000000000113. doi: 10.1097/JU.0000000000000113. [Epub ahead of print]
18. 18. Oh TH, Seo IY The role of Bosniak classification in malignant tumor diagnosis: A single institution experience ICUrology 2016;57:100-105. http://dx.doi.org/10.4111/icu.2016.57.2.100