肾脏甲状腺样滤泡性肾细胞癌的临床病理特征

Clinicopathological characteristics of thyroid-like follicular renal cell carcinoma

目的探讨肾脏甲状腺样滤泡性肾细胞癌(thyroid-like follicular renal cell carcinoma,TLFRCC)的临床病理特征,旨在提高临床和病理医师对TLFRCC的认识,避免误诊、误治。方法对1例TLFRCC病人的临床表现、组织学特征、免疫表型进行观察,并结合国内外相关文献总结其临床病理特征。结果TLFRCC多发生于中年女性,右肾多发,肿块呈结节状,边界较清,部分可见纤维性假包膜,切面灰白色,可见出血和囊性变。镜下肿瘤由大小不一的甲状腺样滤泡构成,滤泡腔内含嗜酸性胶质样物。瘤细胞常表达AE1/AE3和PAX8,不表达Tg、TTF-1、CAⅨ、RCC、TFE3、WT-1和神经内分泌标记,增殖指数低,部分肿瘤存在EWSR1-PATZ1融合基因突变,大多数病人预后较好,个别病人死于肿瘤进展。结论TLFRCC是一种罕见的、低度恶性的肾肿瘤,肉眼无特殊,镜下结构类似甲状腺滤泡,肿瘤细胞具有肾小管上皮表型和特殊的基因突变,结合二者可以协助肿瘤的精准诊断和鉴别诊断。

Objective The aim of this paper was to help clinicians and pathologists to improve the understanding of thyroid-like follicular renal cell carcinoma(TLFRCC)and avoid misdiagnosis and erroneous treatments by exploring the clinicopathological characteristics.Methods One case of TLFRCC was studied,including the clinical manifestations,histological characteristics and immunohistochemical staining,and the clinicopathological characteristics of TLFRCC were summarized by reviewing domestic and foreign literatures.Results TLFRCC mostly occured in middle-aged women,especially in the right kidneys..They showed a solitary nodular mass as well circumscribed with taupe and grey on the cut surface.Hemorrhage and cystic changes could be seen in some areas.Microscopically,most of tumor cells arranged in thyroid follicular pattern in different sizes.The follicule-like structure was filled with eosinophilic colloid-like material.Immunohistochemical staining showed that tumor cells were positive for AE1/AE3 and PAX8,while negative for Tg,TTF-1,CAⅨ,RCC,TFE3,WT-1 and neuroendocrine markers,with low tumor proliferation index.EWSR1-PATZ1 fusion gene mutation was found in some tumors.The prognoses of most patients were good,but a few patients died from tumor progression.Conclusion TLFRCC is a rare renal epithelial tumor with low-grade malignancy.It looks not special grossly,but similar to thyroid follicles in histomorphology.Tumor cells have renal tubular epithelial phenotype and special gene mutation,which can assist in accurate diagnosis and differential diagnosis of tumors.