Radionuclide turnover studies on ectopic thyroid glands--case report and survey of the literature.

A 72-yr-old woman who had previously undergone partial thyroidectomy for "toxic goiter" and subhyoid gland resection presented with signs and symptoms of ectopic lingual thyroid at the base of the tongue. The combination of lingual subhyoid and pretracheal thyroid is a rarity with only three cases reported. Discovery of ectopic thyroid tissue should raise suspicion of other ectopic thyroid tissues along the path of embryologic migration from its origin to the porta hepatis. This may necessitate assessment of radionuclide uptake and imaging of numerous areas. Sodium levothyroxine is the mainstay of therapy. In patients with obstructive symptoms, 131I ablation of the ectopic thyroid tissues has proven successful and may be more advantageous than surgery. In addition, radioiodide studies during ablation therapy gave new information that the ectopic lingual thyroid had more rapid iodide turnover compared with the postsurgical pretracheal thyroid gland.