Nodular fasciitis is a self-limited myofibroblastic lesion that can be misdiagnosed as a sarcoma as a result of its rapid growth, cellularity, and sometimes prominent mitotic activity. Nodular fasciitis (NF) is a common benign mesenchymal lesion that may progress through myxoid, cellular, and fibrous phases. The differential diagnosis of NF includes many other spindle cell neoplasms and it may be misdiagnosed as a sarcoma due to its rapid growth and active mitotic activity. Recently, it was discovered that the entire coding region of ubiquitin-specific peptidase 6 (USP6), an oncogene translocated in aneurysmal bone cyst (ABC), is fused to the MYH9 promoter region in up to 92% of NFs. This finding indicates a potential application of USP6 gene expression or gene break-apart as a biomarker of NF. However, the sensitivity and specificity of USP6 as a biomarker for nodular fasciitis is not known.