Abstract:

Objective To explore the clinicopathologic features，treatment and prognosis of cystic nephroma（CN）.

Methods The clinical data of 6 patients with pathologically confirmed CN from January 2000 to March 2019 were retrospectively analyzed，pathomorphological characteristics and immunophenotype of the tumor were observed and analyzed by HE and immunohistochemistry，and all patients were followed up.

Results All the 6 patients of CN were female patients，aged from 22 to 61 years old，with the median age was 46 years old.In the Bosniak classification，there were 5 cases of grade III and 1 case of grade IV.4 patients underwent partial nephrectomy，2 patient underwent radical nephrectomy.The pathomorphological features of CN showed multilocular cystic structure and composed of epithelial and stromal components.All the 6 patients expressed cytokeratin pan（CK pan），cytokeratin 7（CK 7），smooth muscle actin（SMA），Vimenti，estrogen receptor（ER）and Desmin，and 6 patients expressed progesterone receptor（PR，5/6），CD 10（2/6）and Inhibin（2/6）with varying levels.There was no recurrence or metastasis during a median follow-up period of 58（range 1231）months.

Conclusion CN is a rare benign tumor，which is difficult to be differentiated from other renal cystic diseases by radiological examination because of the similarity of their radiological features.Its precise diagnosis relies on pathologic and immunohistochemical examination.Nephron sparing surgery is suggested for treatment of CN for its good prognosis.

Key words: cystic nephroma, clinicopathologic characteristics, prognosis