CK7阳性/CD117阴性的低级别嗜酸细胞肾肿瘤的临床病理分析

CK7+/CD117-low grade oncocytic tumor of the kidney:a clinicopathological analysis

目的探讨CK7阳性/CD117阴性的低级别嗜酸细胞肾肿瘤(low grade oncocytic tumor of kidney,LOT)的临床病理特征、免疫组织化学表达及分子特征,以增强病理医师对该类肿瘤的认识。方法对浙江大学医学院附属第一医院病理科2017年1月至2021年4月间7例LOT的临床资料、组织学形态及免疫表型进行总结并随访预后,其中5例进行高通量DNA靶向测序,分析其分子特征。结果患者年龄59~82岁,平均70岁。男性2例,女性5例。肿物境界清楚,无纤维化包膜。肿瘤细胞胞质嗜酸,细胞核圆形或卵圆形,可见嗜碱性小核仁,WHO/国际泌尿病理协会2级,核周可见空晕。细胞丰富区,肿瘤细胞以密集的实性、巢状等结构为主,间质可见扩张的静脉、厚壁的小动脉及粗大的胶原纤维束将细胞分割成的假结节。在细胞稀疏区,肿瘤细胞排列形成“组织培养”的外观,其间质黏液样变。此外,间质含有新鲜的出血灶及淋巴细胞聚集灶。高通量测序1例为MTOR基因错义突变,1例为TSC1移码突变。结论LOT是一种惰性肿瘤,具有良好的预后,对于此类病变,病理医师应当注意不要将其误诊为肾嗜酸细胞瘤和嫌色细胞肾细胞癌。

Objective To investigate the clinicopathological,immunohistochemical and molecular characteristics of low grade oncocytic tumors(LOT)of the kidney with CK7+/CD117-staining pattern for enhancing the understanding of renal LOT.Methods The clinical data,histological morphology and immunophenotypes of seven renal LOT cases diagnosed at the Department of Pathology,the First Affiliated Hospital,Zhejiang University School of Medicine from January 2017 to April 2021 were analyzed.The patients were followed up.Among the seven patients,five underwent high-throughput DNA targeted sequencing,and their molecular characteristics were analyzed.Results The patients′age ranged 59-82 years,with an average of 70 years.There were 2 males and 5 females.The boundary of the tumor was clear.The tumor cells had homogeneous eosinophilic cytoplasm and round or oval nuclei,with a perinuclear halo.Small basophilic nucleoli were conspicuous(WHO/International Society of Urological Pathology grade 2).In the hypercellular areas,the tumor cells were mainly arranged in dense solid or nest.In the stroma,there were dilated veins,thick-walled arterioles and thick collagen fiber bundles that divided the cells into pseudonodules.In the sparsely cellular area,the tumor cells were arranged in the so-called"tissue culture"fashion.In addition,the stroma contained fresh hemorrhagic foci and lymphoid aggregates.High-throughput sequencing of 5 cases revealed that one case harbored mTOR gene missense mutation and another case harbored TSC1 frameshift mutation.Conclusions LOT of the kidney is an indolent tumor with an overall good prognosis.Pathologists should not misdiagnose it as renal oncocytoma and chromophobe renal cell carcinoma.