Unusual fusion gene rearrangements in patients with nodular fasciitis: a study of rare and novel USP6 fusion partners with a review of the literature

Abstract

AimsThis retrospective non-randomised study aims to identify new and rare fusion partners withUSP6in the setting of nodular fasciitis. It has been proven, that nodular fasciitis can harbour different variants ofUSP6fusions, which can be used in routine diagnostics and even determine the biological behaviour of the process.MethodsA total of 19 cases of nodular fasciitis examined between 2011 and 2022 at Motol University Hospital in Prague were included into this study. Next to the histopathological evaluation, all cases were assessed using immunohistochemistry, RT-PCR and Anchored multiplex RNA methods. Patient’s main demographic characteristics and corresponding clinical data were also analysed.ResultsThis study presents one novel (KIF1A) and five rare examples (TMP4, SPARC, EIF5A, MIR22HG, COL1A2) of fusion partners withUSP6among 19 cases of nodular fasciitis.ConclusionIdentification ofUSP6fusion partners in nodular fasciitis helps to understand the biology of such lesions. Moreover, it can be useful in routine histopathological practice of soft-tissues diagnostics, especially in preventing possible misdiagnosis of malignancy.