The first case of proliferative fasciitis of tongue coexistent with squamous cell carcinoma: Case report of a rare lesion.

Proliferative fasciitis (PF) is a rare pseudosarcomatous myofibroblastic benign tumor, a subcutaneous counterpart of proliferative myositis. Usually seen in upper extremities, no case has yet been documented in tongue or any other subsites in oral cavity. The present case becomes the first to be reported at this site as well as the first case of synchronous coexistent PF with squamous cell carcinoma (SCC) of tongue. The patient was 50 years male, having a polypoidal swelling at right lateral border of tongue with an ulcer adjacent to it. Histopathologically, the swelling was diagnosed as PF and ulcer as SCC; both the diagnoses were confirmed by immunohistochemistry. The polypoidal lesion was immunopositive for smooth muscle actin and calponin and immunonegative for pan cytokeratin, cytokeratins (5/6), P40 and P63, proving it to be a non-SCC lesion, different from its adjacent ulcerative one.