RESUMO
Purpose To exp1ore the c1inicopatho1ogica1 features,diagnosis and differentia1 diagnosis of mu1ti1ocu1ar cystic rena1 ce11 carcinoma( MCRCC). Methods 18 cases of MCRCC were reported by microscopy,immunohistochemistry,differentia1 diagnosis and were fo11owed-up. Results A11 patients were adu1ts inc1uding twe1ve ma1es and six fema1es who aged from 26 to 68 years(mean 55. 6 years). Imaging studies revea1ed a po1ycystic mass,with c1ear boundary. Gross1y,the cut surface of the tumors had more cysts of va-rying sizes,containing serous or b1oody f1uid. Microscopica11y,the cyst wa11s of tumors were often covered with a few simp1e c1ear ce11s,stratified epithe1ium or devoid of epithe1ium. The septa contained aggregates of epithe1ia1 ce11s with transparent cytop1asm which showed gradeⅠ nuc1ear features,these characteristics were diagnostic c1ues of MCRCC. Immunohistochemica11y the c1ear ce11 was positive for CD10,vimentin,EMA and Ki-67 showed 1ow pro1iferative activity. 18 case were fo11owed up,mean fo11ow-up 43 months, no case recurred or with metastasis. Conclusion MCRCC is a rare histo1ogica1 subtype of rena1 ce11 carcinoma with more favorab1e prognosis. It shou1d be distinguished from cystic change of c1ear ce11 rena1 carcinoma and cysts of kidney 1esion.