- Thin, no palpable thyroid.
- Elevated total T4 and free T4.
- Absent ventral cervical radionuclide uptake.
- Focal increase in radionuclide uptake ventral laryngeal region on midline.
Hyperthyroidism secondary to ectopic sublingual thyroid adenoma.
The patient was treated and became euthyroid. He began to gain weight and had resolution of his polyuria and polydypsia.
The foramen caecum, is a small pouch that forms on the floor of the embryonic pharynx and represents the location of the origin of the epithelial proliferation that becomes the thyroid. The migration path of the thyroid from its embryologic origin in the pharynx along the thyroglossal duct normally ends in the cranial cervical region. Note the close proximity of the thyroglossal duct to the basihyoid bone. Ectopic lingual thyroid may appear as a mass in the dorsum of the tongue. Sublingual ectopic thyroid presents in a midline position cranial (suprahyoid), caudal (infrahyoid), or at the level of the hyoid bone.
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