THYROID-GLAND ECTOPIAS

Failures of descent of the medial anlage of the thyroid and incomplete obliteration of its vertical tract lead to midline or near-midline ec topias such as lingual thyroid and thyroglossal cysts. Each poses spec ial diagnostic and therapeutic considerations. ''Ectopias'' of the thy roid gland lateral to the carotid artery and jugular vein, however, ca nnot be readily explained by current embryological information. In the se instances, and especially for intranodal thyroid tissue, a metastas is from an occult thyroid primary is the mandatory first consideration .