Erber R, et al. - This study examined the aspects of diagnosis of nodular fasciitis (NF) and morphologically related reactive myofibroblastic proliferations by appraising lesions with a diagnosis of NF or NF-like myofibroblastic proliferations and by screening them for USP6 translocation through fluorescence in situ hybridization (FISH). Findings reported the USP6 gene translocation as a valuable adjunct for diagnosis of NF, especially in the case of limited biopsies. The absence of the USP6 gene translocation in NF-like reparative pseudosarcomatous myofibroblastic proliferations underscored their reactive nature. Moreover, it distinguished them from NF which was regarded as a benign neoplasm with a self-limiting “transient” growth phase.