Hence, detection of FOSL1 rearrangements by targeted sequencing approaches may be the preferred adjunct for the diagnostic work‐up of fibrous tumours: this resolves the challenge of interpreting equivocal immunohistochemistry while simultaneously identifying genetic alterations that may indicate other fibrous tumours, including desmoid‐type fibromatosis, nodular fasciitis and low‐grade fibromyxoid sarcoma. Here, FOSL1 is linked to nodular fasciitis.