Nodular Fasciitis

odular fasciitis, also known as infiltrative or pseudosarcomatous fasciitis, is a benign soft tissue tumor of fibroblastic/myofibroblastic differentiation that was first described in 1955 by Konwaler et al.1 The lesion often comes to clinical attention when a patient presents with a rapidly growing, occasionally painful, palpable soft tissue mass.2,3 Although benign and self-limited, nodular fasciitis is a clonal neoplastic proliferation characterized by recurrent MYH9-USP6 (myosin heavy chain 9–ubiquitinspecific peptidase 6) gene fusion.4 Despite the fact that in a large retrospective study nodular fasciitis was found to represent 11.3% of benign soft tissue tumors,5 relatively few descriptions of nodular fasciitis have appeared in the radiologic literature. Most of the reports have been published in Anthony Khuu, MD, Corrie M. Yablon, MD, Jon A. Jacobson, MD, Alero Inyang, MD, David R. Lucas, MD, J. Sybil Biermann, MD