多囊性肾细胞癌与肾透明细胞癌囊性变的临床病理分析

Multicystic renal cell carcinoma:a clinicopathologic study with comparison of it with renal clear cell carcinoma undergoing cystic change

目的探讨多囊性肾细胞癌(MCRCC)临床病理特点及其与肾透明细胞癌囊性变(RCCCC)的预后差异。方法1999～2003年收治的多囊性肾细胞癌21例,肾透明细胞癌囊性变11例,行根治性肾切除术或肾部分切除术。由两位病理医生独立观察,比较多囊性肾细胞癌和经典肾透明细胞癌伴有明显囊性变的病理特征和预后的差异。结果21例MCRCC患者中,男性17例,女性4例,年龄37～67岁,平均年龄49岁。15例MCRCC患者有详细的随访资料,随访时间为31～73个月,患者平均生存时间为61个月,无复发或转移。7例有随访资料的RCCCC病例平均存活32个月(随访时间为18～63个月),两组间比较有显著性差异(P<0.05)。组织学上多囊性肾细胞癌多数界限清楚,周围有较厚的包膜,瘤体内实性成分较少,由多个互不相通、大小不一的囊腔组成,Fuhrman核分级多数为1级;而肾透明细胞癌囊性变病例可见明显的实性区域,由典型的透明细胞组成,其中可见大小不一的囊腔,囊腔之间为透明细胞,无多囊性肾细胞癌的纤维组织囊壁。结论由于MCRCC具有良性肿瘤特征和特殊的病理学表现,其临床预后明显好于RCCCC,对怀疑并证实MCRCC者应该考虑施行保留肾单位手术。

Objective Multicystic renal cell carcinoma （MCRCC） appears to be a distinct subtype of renal cell carcinoma with characteristic gross and microscopic features. To explore the clinical and pathological features of MCRCC in order to find out its difference from renal clear cell carcinoma undergoing cystic change （RCCCC）, and to propose prognosis criteria for therapeutic modalities. Methods From 1999 to 2003 32 patients were identified to have renal carcinoma, and they received radical or partial nephrectomy in the authors＇ institution. The pathological diagnosis was either MCRCC （n=21） or renal cell carcinoma associated with features of cystic changes （n= 11）. All specimens were reviewed histologically by two independent pathologists. The clinicopathologic and follow-up prognosis data on MCRCC and RCCC were collected for study. Results 21 patients with MCRCC were 17 men and 4 women. The mean age at the time of surgery was 49 years （range 37 to 67 years）. 15 MCRCC patients with follow-up data were still alive with a mean follow-up time of 61 months （ranged 31 to 73） and no evidence of recurrence and metastasis was discovered. The mean survival time for 7 of the 11 patients with RCC was 32 months （ranged 18 to 63）. There was significant difference in survival time between the two groups （P〈0. 05）. Histologically, the MCRCC showed well-demareated multicystic lesions containing aggregates of neoplastic clear cells in variable size, showing Fuhrman grade 1 nuclear features with little or no mitotic activity. The cyst walls were densely fibrotic, and the lining was often devoid of epithelium. In contrast, the renal clear cell carcinoma with cystic changes showed prominent solid areas of typical clear cell carcinoma. Cysts in various size were separated by clear cell carcinoma rather than fibrous septa which were frequently seen in MCRCC. Conclusion MCRCC may represent a histologically distinct benign neoplasm, and its presence in association with RCCCC may corder a more favorable prognosis. Its distinction from typical RCCCC is important. The authors believe that MCRCC is a low-grade variant and should be studied further to determine appropriate therapy. Nephron sparing surgery should be proposed when MCRCC is suspected.