Nodular fasciitis in the buccal region with rapid growth after incisional biopsy mimicking sarcoma.

Nodular fasciitis (NF) is a reactive and proliferative fibroblastic lesion that occurs predominantly in the upper limbs but rarely develops in the oral cavity. This lesion can be misdiagnosed as malignant owing to its frequent display of rapid growth, rich cellularity, and high mitotic activity. Unlike a sarcoma, NF can resolve spontaneously or after an incisional biopsy. We describe a challenging case involving a lesion in the buccal region that rapidly enlarged after incisional biopsy. This variation of clinical behavior illustrates the difficulty in predicting whether NF will continue to grow or regress. Clinicians dealing with cases of an enlarging fibrous lesion of short duration should remain aware of this disease entity and its potential diagnostic dilemma.