Reassessment of the treatment of Bosniak category II-m renal cyst

Objective To reassess the treatment of Bosniak category Ⅱ-Ⅲ renal cyst.Methods Sixty-eight cases of Bosniak category Ⅱ-Ⅲ renal cyst were operated from 2005 to 2008 in our institute.The average patient age was 40 years with the average renal cyst diameter of 5.1 cm.There were 37 left lesions and 31 right lesions with 31 cases of category Ⅱ (including 13 cases of category Ⅱ F) and 37 cases of category Ⅲ.Renal unroofing were performed in 49 cases with 9 cases found malignant and followed by radical nephrectomy,19 cases were diagnosed as malignancy preoperatively and nephron sparing surgery or radical nephrectomy were performed in these cases.Results Malignant lesions were found in 21 cases and benign lesions were found in 47 cases.The malignant rate was 9.7％ in category Ⅱ (15.4％ in category Ⅱ F),48.6％ in category Ⅲ.Nine cases were diagnosed benign preoperatively but confirmed malignancy after operation; 7 cases were diagnosed malignancy preoperatively but confirmed benign after operation.Forty-two cases were followed up for 8-65 months with 15 cases of malignancy and 27 cases of benign lesions.The recurrence of renal cyst occurred in 6 cases of benign lesions and recurrence and metastasis occurred in 3 cases of malignancy in 1-5 years.Conclusions It is difficult to draw a therapeutic principle for Bosniak category Ⅱ-Ⅲ renal cyst because of the uncertainty of the lesion.Partial nephrectomy or renal cystectomy is a good choice in the treatment of Bosniak category Ⅱ-Ⅲ renal cysts.\r\n\r\nKey words: \r\nRenal cyst;  Bosniak renal cyst classification;  Malignant tumor