A 34-year-old woman with nodular fasciitis arising in the right masseter muscle is reported.
The patient had an indolent, 2-cm mass in the right buccal region. The mass had been present for 2 months. Ultrasonography, MRI, and cytological examination revealed a benign tumor arising in the masseter muscle.
She underwent peroral excision of the mass. Histopathologic examination of the surgical specimen revealed a well encapsulated mass composed of proliferations of immature fibroblasts within a myxomatous matrix, accompanied by proliferations of capillaries and infiltration of inflammatory cells. However, fibroblasts showed neither polymorphism nor atypia. From these findings, the mass was diagnosed as nodular fasciitis.
The postoperative course was uneventful, and 1 year 9 months postoperatively the patient was well, with no signs of recurrence.