ABSTRACT
Objective To evaluate the application significance of Bosniak renal cyst classification. Methods The operations of 497 cases of cystic renal masses were performed from 2002 to 2007 in our hospital.The average age of these cases was 42-years old,the average diameter of renal cysts was 5.4 cm. There were 212 left lesions,265 right and 20 bilateral.According to Bosniak classification,there were 339 cases of category I,49 cases of category Ⅱ(including 23 cases of category ⅡF),44 cases of category Ⅲ and 65 cases of category Ⅳ.Renal cystectomy was performed in 372 cases when nephron sparing surgery performed in 51 eases and radical nephrectomy performed in 74 cases.Results Malignant tumors were found in 89 cases and benign lesions were found in 408 cases.The malignant rate was 0.9% in category I,10.2% in category Ⅱ(13.O%in category ⅡF),52.3% in category Ⅲ,89.2% in category Ⅳ.There was significant difference among the 4 groups,but there was no significant difference between category ⅡF and non-Ⅱ F of category Ⅱ.403 cases were followed up for 1-5 years with 75 cases of malignancy and 328 cases of benign lesions.Recurrence or metastasis was found in 9 malignant cases.Conclusions Careful follow-up should be performed in category I and Ⅱ,especially in the cases of Ⅱ F category and the eases with changes of diameter or morphology.It is definite that surgery should be performed in the cases of renal cyst with category Ⅲ or Ⅳ for their high malignant rate.