Thyroid tissue as a submandibular mass: a case report.

Ectopic thyroid gland is a rare phenomenon that appears most frequently in the cervical midline and very rarely in other sites such as the submandibular region. This article reports a painless, non-tender and firm thyroid tissue mass in the right submandibular region of a 29-year-old female patient. Physicians should consider ectopic thyroid tissue as a differential diagnosis of submandibular swellings and be aware that this ectopic gland is the only functional thyroid tissue in 70% of cases.