I measured the incidence and main characteristics of complicated renal cysts. From 01 January 2000 to 01 January 2015, a total of 1272 patients underwent surgery for suspicion of renal tumor at the Department of Urology, University of Debrecen. The majority of renal tumors were detected by ultrasound examinations. Thereafter contrast enhanced CT (computed tomography) was performed. The radiomorphological imaging examinations showed complicated renal cysts in 38 patients (3%). Bosniak III and IV cysts were defined complicated renal cysts. In these patients, due to the suspicion of malignancy radical nephrectomy or partial nephrectomy were performed depend on the tumor size and the t umor localization. Histology of the removed complicated renal cysts proved renal cell carcinoma in 12 cases (31.5%), while benign renal cyst was present in 26 cases (68.5%). In patients with complicated renal cysts , radical nephrectomy was p erformed in 18
patients and tumor resection was carried out in 20 cases. For the radical nephrectomy and for the nephron sparing surgery we administ ered open surgical procedures and laparoscopic interventions as well. The mean age of the patients with complicated renal cysts was 55±12 years (range from 24 to 81 years). In patients with complicated renal cysts there were 13 (34%) females and 25 (66%) m ales. There were 15 cysts in the right kidney, while in 23 patients the ren al cyst was in the left kidney. The mean diameter of the complicated renal cysts was 4.1±2.1 cm (range from 1.4 to 9.2 cm). The tumor size of the renal cysts was ≤4 cm in 22 patien ts and it was > 7 cm in 4 cases. The preoperative and postoperati ve serum hemoglobin levels, the creatinine concentrations and the estimated glomerular filtration rate (GFR) were recorded. The histology of the removed specimens showed malignancy in 12 pati ents and benign renal cyst in 26 occasions. The mean size of the cysts with malignant component was 5.4±2.1 cm, while it was 3.4±1.8 cm in benign renal cysts. The size of the benign renal cysts showed significant deviation from malignant tumors (p=0.005). In conclusion, the rate of the malignancy related to renal cysts is relatively low. However, sometimes based on the imaging examinations we are unable to exclude the presence of malignancy when the patient has renal cyst. In these cases surgery is recommended. Our results showed presence of alignancy in 31.5 % of Bosniak III and IV cysts.