Rhabdomyosarcoma of mandible: A diagnostic predicament.

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children under 15 years of age and rare among persons older than 45 years of age. It is considered to result from malignant transformation of primitive mesenchymal cells. Although it has a relative predominance for head and neck region, it is found less often in oral cavity. Here we report a case of RMS of mandible in an adult patient, which was initially diagnosed as carcinosarcoma. Clinical and pathologic findings are described, which were confirmed by histochemical and immunohistochemical stains.