肾细胞癌伴肉瘤样分化的临床病理特征及预后

Clinicopathological features and prognosis of renal cell carcinoma with sarcomatoid differentiation

目的探讨肾细胞癌伴肉瘤样分化（RCCS）的临床病理特征及预后。方法对18例RCCS患者的临床病理特征进行分析，并与同期20例不伴肉瘤样分化的肾透明细胞癌进行比较。结果18例RCCS患者中，男性14例，女性4例。年龄49～79岁，平均年龄62岁。肿瘤直径为3—19cm，平均为9．8cm。镜下观察显示，肿瘤均由比例不等的肾细胞癌和肉瘤样成分组成，其中透明细胞癌14例，嫌色细胞癌3例，乳头状细胞癌1例；肉瘤样成分表现为纤维肉瘤样9例，平滑肌肉瘤样3例，恶性纤维组织细胞瘤样5例，未分化肉瘤样1例。免疫组化检测显示，18例RCCS的肉瘤样成分均呈波形蛋白（vimentin）强阳性；14例RCCS的肉瘤样成分表达1项或几项上皮性标记物（EMA、AE1／AE3、CK7、CK18），但高分子量角蛋白34βE12表达很少。RCCS的肉瘤样成分碳酸酐酶Ⅸ（CAⅨ）阳性16例（88．9％），CD10阳性13例（72．2％）。18例RCCS患者中，13例获得随访，有9例于术后1～25个月死亡，其中死于肺和骨等转移5例，死于全身衰竭4例。20例肾透明细胞癌不伴肉瘤样分化患者随访3～65个月，除2例死于肺和骨转移外，余均健在。生存分析显示，18例RCCS患者的中位生存时间为8个月，20例肾透明细胞癌不伴肉瘤样分化患者的中位生存时间为62个月，差异有统计学意义（P〈0．001）。结论肾细胞癌出现肉瘤样分化是肾细胞癌去分化的形态学表现，具有高度侵袭性及不良预后。CAIX和CDl0在肾细胞癌发生肉瘤样转化的过程中可能具有重要作用。

Objective To study the clinicopathological features and prognosis of renal cell carcinoma with sarcomatoid differentiation （RCCS）. Methods The clinical data and pathological materials of 18 RCCS cases were retrospectively reviewed.The follow up data were available in 13 RCCS cases, and were compared with the follow up data of 20 cases of clear cell renal cell carcinoma （ RCC ）. Results The 18 RCCS patients included 14 males and 4 females, and were 49-79 years old （mean age： 62 years old）. On gross examination, the tumor size was 3-19 cm in diameter （mean diameter： 9.8 cm）. Histologically, all tumors were composed of a mixture of typical RCC with sarcomatoid component, including 9 clear cell RCC, 3 chromophobe RCC and one papillary RCC. The sarcomatoid components included 9 cases of fibrosarcoma, 3 cases of leiomyosarcoma, 5 cases of malignant fibrous histocytoma and one case of undifferentiated sarcoma. Immunohistochemistry showed that the sarcomatoid components were strongly vimentin-positive in 18 cases, and one or more epithelial markers （EMA, AE1/AE3, CK7, CK18） were expressed to varying degrees in 14 cases, but the high-molecular weight keratin 3413E12 was scarcely expressed. The sarcomatoid components presented positive expressions of CAⅨ in 88.9% （16/18） and CD10 in 72.2% （13/18） cases. Among the 18 RCCS patients, 13 patients were followed-up： 9 patients died in 1-25 months after the surgery, of which 5 cases died of lung or bone metastasis, and 4 patients died of systemic failure. The twenty RCC cases without sarcomatoid differentiation were followed up for 3-65 months after the surgery, and the majority of them was alive uneventfully except for 2 cases who died of lung or bone metastasis of the tumor. The Kaplan-Meier survival analysis showed that the median survival time of the 18 RCCS patients was 8 months, while that of the 20 RCC cases without sarcomatoid differentiation was 62 months （P〈0.001）. Conclusions The presence of sarcomatoid differentiation in renal cell carcinoma indicates highly aggressive behavior and poor prognosis. The positive expressions of the immune markers CAⅨ and CD10 may play important roles in the transformation from renal cell carcinoma to sarcomatoid component.