Thyrotoxicosis in a patient with submandibular thyroid

Ectopic thyroid glands generally appear in the midline due to abnormal medi an migration; their presence lateral to the midline is rare. We report the case of a 42-year-old female who presented with symptoms of thyrotoxicosis and an expanding submandibular swelling. Tc-99m-sodium pertechnetate scanni ng showed thyroid tissue in the left submandibular region, while no thyroid tissue was seen in the normal site. The patient was treated with 10 mCi of I-131 and subsequently became euthyroid. Literature review revealed seven cases of lateral aberrant thyroid tissue. The theories to explain lateral a berrant thyroid are presented.