Original Articles

Clinical and Pathological Features of Bosniak Type III and Type IV Renal Cysts: A Six Year Experience


  • Tarık Yonguç
  • Deniz Bolat
  • Özgü Aydoğdu
  • Hülya Mollamehmetoglu
  • İbrahim Halil Bozkurt
  • Bülent Günlüsoy
  • Volkan Şen
  • İsmail Basmacı

Received Date: 01.03.2015 Accepted Date: 01.05.2015 Bull Urooncol 2015;14(3):174-177


In this study, it was aimed to evaluate the clinical and pathological outcomes of the patients with complex renal cysts managed surgically.

Materials and Methods:

Records of 108 patients with Bosniak type III and IV cystic renal masses managed with partial or radical nephrectomy between 2008 and 2014 were reviewed. Renal cysts were classified according to Bosniak classification system by using the preoperative computed tomography (CT) images. The pathology results of the operated complex renal cysts were analyzed and the clinical data of malignant and benign cystic renal masses were compared.


A hundred and eight patients were operated for complicated renal cysts and 98 patients whose clinical data could be obtained were included in the study. The mean age was 57.3±12.3 (27-82) years and the mean cyst size was 6.6±3.6 cm (2-28 cm), 53 (54%) patients were males and 54 (55.1%) cysts were on the left side. According to the preoperative evaluation of cysts; 21 (21.4%) cysts were diagnosed as Bosniak type III cysts and 77 (78.6%) cysts were diagnosed as Bosniak type IV. Of the 98 patients, 74 were asymptomatic and the most common symptom was flank pain (16.3%). Malign cyst was diagnosed in 76 patients (77.6%). Malignancy rates were 52.4% and 83.1% in Bosniak type III and type IV cysts, respectively. Of the 76 malign cysts 54% showed clear cell renal carcinoma. Of the 22 benign tumors 50% were benign cyst and 27.3% showed angiomyolipoma. Of the 68 renal cell carcinomas 36.8% was in T1a stage and 62.5% were Fuhrman grade 2. Risk factors for the malignancy potential of the complex renal cysts were advanced age, higher cyst size, male gender and higher Bosniak score.


Big-sized cystic renal masses especially in male patients with advanced age should be considered for malignancy and surgical management should be kept in the forefront.

Keywords: Renal cysts, renal tumors, Bosniak classification, imaging, surgical outcomes

Full Text (Turkish)