congenital malformation of the thyroid
Last reviewed 01/2018
The embryological line of descent of the thyroid gland, from the region of the foramen caecum of the tongue to its normal position in the neck, may be the site of fistula or cyst formation.
On rare occasions the thyroid fails to descend properly into the neck and such a patient may present with a lump in the foramen caecum - lingual thyroid - or at the front of the neck near the body of the thyroid bone. Such a swelling may not be suspected as being thyroid and if this is removed then the patient may have no other functioning thyroid tissue. In all cases of unexplained nodules in the line of thyroid descent, a radio-iodine scan should be performed to ensure that there is normal thyroid tissue in the correct place before the lump is removed.
Occasionally the thyroid descends beyond its normal station into the superior mediastinum - a retrosternal thyroid.