Nodular fasciitis of the nasal cavity with USP6 rearrangement: a case report

Abstract

Nodular fasciitis (NF) is a benign myofibroblastic tumor characterized by rapid growth, self-limiting course, and rearrangement of the USP6 gene. While NF can occur in the head and neck region, cases originating within the nasal cavity are exceedingly rare. We herein report a case of NF in the nasal vestibule of a female patient, presenting as a polypoid mass with surface erosion and bloody discharge. The lesion progressively enlarged, resulting in obstructive symptoms. Histopathological and immunohistochemical findings were diagnostic of NF despite its unusual location. Fluorescence in situ hybridization (FISH) confirmed a USP6 gene rearrangement. The patient remained free of recurrence 120 months after surgical resection. We summarize the clinicopathological features of this case along with four previously reported cases of nasal NF. Compared with NF at typical sites, nasal NF demonstrates distinctive characteristics, including a female predominance, a predilection for the right side, and a predominantly myxoid histology. Owing to its acute onset, rapid growth, high cellularity, and frequent mitotic activity in the absence of infection, NF often mimics malignant tumors and is frequently misdiagnosed as sarcoma. Given its extreme rarity, nasal NF carries a particularly high risk of being misdiagnosed as malignancy.