摘要
Abstract
Objective:Adult metanephric adenoma is a rare renal tumor with a good prognosis,but which is easily misdiagnosed.This study aims to explore the clinical pathology,immunophenotype,molecular pathological characteristics,differential diagnosis,and prognosis of adult metanephric adenoma,with the goal of increasing pathologists'awareness of this tumor.
Methods:The clinical data of 6 cases of adult metanephric adenoma from the Third Affiliated Hospital of Sun Yat-sen University were collected.HE staining,immunohistochemistry,and molecular testing were performed on the specimens,and relevant literature was reviewed.
Results:Among the 6 cases,4 were female and 2 were male,with a male-to-female ratio of 1꞉2.The mean age was 47.17(range 26-66)years.Five cases underwent partial nephrectomy,and one case underwent total nephrectomy.Microscopic examination showed that the tumor was composed of small,round or oval cells arranged in tubular or papillary structures.The cell morphology was relatively uniform,with sparse cytoplasm,and mitotic figures were rare.The boundaries were clear in 5 cases,while one case had an unclear boundary with the normal kidney and was misdiagnosed as adult epithelial-type nephroblastoma at an outside hospital.Immunohistochemistry showed that all 6 cases expressed cytokeratin(CK)CAM5.2,Wilms tumor 1(WT1),v-Raf murine sarcoma viral oncogene homolog B1(BRAFV600E),and vimentin.Five cases expressed CD57,neural cell adhesion molecule(CD56),cytokeratin 7(CK7)and α-methylacyl-CoA racemase(P504S)focally or negatively,while none expressed epithelial membrane antigen(EMA),desmin,CD117,common acute lymphoctte leukemia antigen(CD10),or carbonic anhydase IX(CAIX).The Ki-67 proliferation index was low,with a positive rate of 1%-5%.Next-generation sequencing(NGS)or reverse transcription PCR(RT-PCR)detected BRAFV600E mutations in all 6 cases.Follow-up lasted for 7-96 months,and no recurrence or metastasis was observed.
Conclusion:Metanephric adenoma is a benign tumor with a good prognosis and no recurrence or metastasis.It is often misdiagnosed as epithelial-type nephroblastoma.关键词
后肾腺瘤/临床病理特征/免疫组织化学/鼠类肉瘤滤过性毒菌致癌基因同源体B1/上皮型肾母细胞瘤Key words
metanephric adenoma/clinicopathological characteristics/immunohistochemistry/v-Raf murine sarcoma viral oncogene homolog B1/epithelial-type nephroblastoma
