Ossifying fibromyxoid tumor of oral cavity.

Ossifying fibromyxoid tumor is a rare tumor of mesenchymal origin with varied presentation at different sites including head and neck. Clinically these are slow growing lesions and patients have a variable age at presentation. A 14 years old girl presented with a slowly enlarging gingival swelling, which on radiological examination showed increased rarefaction in the mandible with a provisional diagnosis of an inflammatory lesion. Microscopically, the tumor had spindle to oval shaped cells in a fibromyxoid background with a peripheral shell of lamellar bone. Histological diagnosis of ossifying fibromyxoid tumor was made after immunohistochemical stains for vimentin and S-100 protein. Recurrence, metastasis and histologically increased mitotic count are indicative of atypical or malignant ossifying fibromyxoid tumors.