低级别嗜酸性肾肿瘤3例报告并文献复习

Low-grade oncocytic renal tumor:a report of 3 cases and literature review

目的总结3例低级别嗜酸性肾肿瘤(LOT)患者的临床信息、影像学表现、病理表现及预后,提高临床对该疾病的认识。方法回顾性分析北京大学第三医院2020年2月—2022年9月收治的3例LOT患者的临床资料、影像学表现、病理资料及术后随访情况。结果3例确诊为LOT的患者均为男性,年龄51~70岁,肿瘤最大径14~21 mm,均为单发。患者均无特殊临床表现,计算机断层扫描示类圆形等密度影。3例患者均行保留肾单位的肿瘤切除术。大体标本的切面为棕黄色或棕色,肿瘤呈实性或部分区域囊实性。HE染色可见细胞质呈均匀的嗜酸性,细胞核呈圆形或椭圆形,局部可能有细微的核周空晕。免疫组化示CK7(+)、CD117(-)。病例2行基因检测提示可能具有临床意义的体细胞变异1个(结节性硬化症2基因)。术后随访时间12~23个月,随访期间肿瘤均未复发。结论LOT在临床症状与影像学上无明显特征,在组织形态学上表现出与肾嗜酸细胞瘤和肾嫌色细胞癌杂合性或交界性的特征,生物学行为呈惰性表现,行保留肾单位的肿瘤切除术,患者预后良好。

Objective To review the clinical information,imaging features,pathological manifestations and prognosis of low-grade oncocytic tumor(LOT),so as to improve the clinical understanding of the disease.Methods The imaging,clinicopathological and postoperative follow-up data of 3 LOT cases treated in Peking University Third Hospital during Feb.2020 and Sep.2022 were retrospectively collected.Results All patients were male,aged 51—70 years.All tumors were single,with the maximum diameter of 14—21 mm.None of the patients had any specific clinical manifestations.The mass showed a circular isodense shadow on CT.All patients underwent nephron-sparing tumor resection.Postoperative pathology showed that the incision surface of the tumors was brownish-yellow or brown,and the tumors were solid or partially cystic.HE staining showed that the cells were uniformly eosinophilic;the nucleus was round or oval,with slight local perinuclear halo.Immunohistochemistry showed positive CK7 but negative CD117.Genetic testing in case 2 showed 1 potentially clinically significant somatic mutation TSC2.During the follow-up of 12-23 months,no recurrence occurred.Conclusion There were no obvious clinical symptoms and imaging features of LOT,which morphologically showed heterozygous or borderline characteristics with renal eosinophilia and renal chromophobe cell carcinoma,and the biological behavior was indolent.Nephron-sparing tumor resection promised good prognosis.