Occult thyroid carcinoma appearing as a single mandibular metastasis.

Extraglandular well-differentiated follicular thyroid tissue in the head and neck can originate from aberrant embryologic rests, by separation from the main gland through strap muscle action, by 'benign metastatic" seeding of the cervical lymphatics, and from mixed papillary-follicular or pure follicular carcinoma. The management of this ectopic tissue is controversial. A case of occult follicular carcinoma with a sole metastasis to the mandible is presented.