后肾腺瘤2例临床病理观察

Clinicopathological features of metanephric adenoma: a report of two cases

目的总结和分析后肾腺瘤的临床病理及分子遗传学特征。方法回顾性复习2例后肾腺瘤,并结合文献探讨后肾腺瘤的临床表现、组织学特征、免疫表型及分子遗传学特点。结果 2例肿瘤均位于右肾,大体界限清晰,无包膜;其中例1为男性,68岁,镜下表现为紧密排列的小腺管,细胞小而一致,核分裂罕见,可见散在砂砾体。例2为女性,61岁,镜下高度富于细胞,肿瘤细胞呈实性片状或巢状排列,并见明显坏死,瘤细胞具有轻~中度异型。免疫组化标记示2例均表达vimentin和CD57,不同程度表达上皮标记及p16,其中1例表达WT1和CDH17。2例均不表达CK7、CD10及CD56。2例均检测出BRAF基因V600E位点的突变。结论后肾腺瘤为罕见的良性肾脏上皮性肿瘤,术前临床和影像学多考虑恶性,明确诊断主要依靠病理检查,对于诊断困难的病例可借助免疫组化和BRAF基因V600E突变检测来辅助诊断。

Objective To summarize and analyze the clinicopathological features and molecular genetic characteristics of metanephric adenoma. Methods Two cases of metanephric adenoma were retrospectively analyzed,and the clinical characteristics,histological features,immunophenotypic and molecular genetic features of metanephric adenoma were analyzed with review of literature. Results Both tumors were located in the right kidney with clear gross boundary and no capsule. Case 1 was composed of closely arranged small glandular ducts with small and uniform cells,rare mitosis and scattered psammoma bodies. In case 2,the tumor was highly cellular. The tumor cells showed a solid lamellar or nest like structure with obvious necrosis. The tumor cells had light to medium heteromorphism. Vimentin and CD57 were expressed in both cases,and epithelial markers and p16 were expressed in different degrees. WT1 and CDH17 were expressed in one case. CK7,CD10 and CD56 were not expressed in both cases. The mutation of BRAF V600 E was detected in both cases.Conclusion Metanephric adenoma is a rare benign renal epithelial tumor. Preoperative clinical and imaging diagnosis usually consider malignancy,and definite diagnosis needs pathological examination. For cases with difficult diagnosis,immunohistochemistry and BRAF V600 E mutation can be used to assist the literature diagnosis.