Mandibular metastasis of thyroid carcinoma: a case report.

Metastatic carcinomas to the jaw bones are uncommon and comprise to about 1% of all malignant oral neoplasms. It may be the first indication of an unknown malignancy from a distant primary site which is usually associated with poor prognosis. We report a rare case of thyroid carcinoma metastatic to the mandible in a 76-year-old elderly male patient in which the lesion was asymptomatic. Microscopic examination revealed a tumour structure consisting of cords and islands of infiltrating epithelium. The immunohistochemical marker, thyroid transcription factor -1 was done which showed a positive staining by the follicular cells. The tumour was diagnosed as metastatic follicular thyroid carcinoma. It should be emphasized that histopathological diagnosis along with panel of markers play an important role in diagnosing the site of origin of bone metastasis and these lesions should be included in the differential diagnosis of asymptomatic jaw lesions.