Ectopic thyroid is any thyroid tissue located outside its normal topography, which may present itself along the median line of the neck or, more rarely, in the lateral cervical region. Some theories seek to explain the origin of ectopic thyroid tissue as: 1. Failure in descent of the gland; 2. Occlusion of thyroid nodules; 3. Presence of thyroid tissue in the cervical lymph node capsules; 4. Teratomatous formation; 5. Secondary to branchial anomalies. For diagnosis, a number of exams have been used, the definitive diagnosis sometimes being provided only by a histopathological study. Despite the controversies in relation to therapeutic approaches presented in the literature, rigorous planning is necessary in order to avoid iatrogenias. It is concluded that the presence of ectopic thyroid tissue should be remembered upon diagnosis of differential lateral cervical masses, and its histological origin considered, it most often being metastasis of an occluded thyroid carcinoma. The authors present a case of ectopic lateral neck thyroid tissue, in a woman aged 42 with atoxic multinodular goiter. Important considerations were accomplished about the theories to explain the origin of ectopic thyroid tissue, diagnostic methods and treatment options, reviewing the literature of the last five decades.
ectopic thyroid tissue; lateral neck; diagnosis; management
