Publication Date:
2020-10-12
Description:
BackgroundMetanephric adenoma (MA) is a rare benign renal neoplasm. On occasion, MA can be difficult to differentiate from renal malignancies such as papillary renal cell carcinoma in adults and Wilms̕ tumor in children. Despite recent advancements in tumor genomics, there is limited data available regarding the genetic alterations characteristic of MA. The purpose of this study is to determine the frequency of metanephric adenoma cases exhibiting cytogenetic aberration t (9;15)(p24;q24), and to investigate the association between t (9,15) andBRAFmutation in metanephric adenoma.MethodsThis study was conducted on 28 archival formalin fixed paraffin-embedded (FFPE) specimens from patients with pathologically confirmed MA. Tissue blocks were selected forBRAFsequencing and fluorescent in situ hybridization (FISH) analysis for chromosomal rearrangement betweenKANK1on chromosome 9 (9p24.3) andNTRK3on chromosome 15 (15q25.3), which was previously characterized and described in two MA cases.ResultsBRAFV600Emutation was identified in 62% of our cases, 9 (38%) cases wereBRAFWT, and 4 cases were uninformative. Of the 20 tumors with FISH results, two (10%) were positive forKANK1-NTRK3fusion. Both cases wereBRAFWTsuggesting mutual exclusivity ofBRAFV600EandKANK1-NTRK3fusion, the first such observation in the literature.ConclusionsOur data shows thatBRAFmutation in MA may not be as frequent as suggested in the literature andKANK-NTRK3fusions may account for a subset ofBRAFWTcases in younger patients. FISH analysis forKANK1-NTRK3fusion or conventional cytogenetic analysis may be warranted to establish the diagnosis of MA in morphologically and immunohistochemically ambiguous MA cases lackingBRAFmutations.
Electronic ISSN:
1471-2350
Topics:
Biology
,
Medicine
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