Sonographic Features of Dual Ectopic Thyroid: Report of Two Cases

Ectopic thyroid is an uncommon congenital abnormality, but ectopic thyroid tissue can be present anywhere along the course of the thyroglossal duct and the embryologic descent from the base of the tongue. We report here on two cases with the ultrasonograpic findings of dual ectopy of the thyroid, and these findings were well correlated with the findings of nuclear scintigraphy.

Adenomatous Hyperplasia Arising from Dual Ectopic Thyroid

Ectopic thyroid tissue is an uncommon embryologic aberration characterized by the presence of thyroid tissue in a site other than its usual pre-tracheal location. Single ectopic thyroid tissue is the most common variant, and the base of the tongue is the most frequent ectopic location. Dual ectopic thyroid is extremely rare, and only eleven cases have been reported in the English literature. Furthermore, adenomatous hyperplasia has never been reported to arise from dual ectopic thyroid. There has been only one reported case of adenomatous hyperplasia arising from a single intratracheal ectopic thyroid. We report a case of adenomatous hyperplasia arising from dual ectopic thyroid tissue that presented as a sublingual mass in a 37-yr-old woman. The diagnosis was made through pathologic examination after surgical resection. We also discuss the diagnosis and treatment of ectopic thyroid, along with a review of the literature.

A Case of Dual Ectopic Thyroid / 대한이비인후과학회지

Ectopic thyroid is defined as any thyroid tissues not located in the usual site of the thyroid gland, which is anterolateral to 2-4th tracheal rings in the lower neck. These tissues could be present anywhere along the descending tract of a developing thyroid primordium. It is rare for dual ectopic thyroid to have two ectopic foci simultaneously. Twenty-seven cases of dual ectopic thyroid have been reported in the English literature. Physical examinations are usually performed for oral cavity, oropharynx and anterior neck to test for thyroid function, and CT scanning and thyroid scintigraphy are usually performed for the diagnosis of these entities. We report a 19-year-old male with dual ectopic thyroid tissues in lingual and suprahyoid regions but without thyroid tissue in its normal area.

Dual Ectopic Thyroid / 대한이비인후과학회지

Dual ectopic thyroid is an uncommon entity and seven cases have been reported in the literature. Clinically, most cases in ectopic thyroid were noted at adolescence or postpartum due to increased physiologic hormonal demands. The sublingual area is the most common site of ectopic thyroid tissue, accounting for 90% of the cases, followed by the area in high cervical thyroid. Clinical manifestation, thyroid function test, and radiologic imaging should be employed for making diagnosis and therapeutic plan of this disease. The primary therapeutic goal is to restore the thyroid function. We describe a patient with dual ectopic thyroid tissue in the sublingual and subhyoid area.

Dual Ectopic Thyroid: A Case Report / 대한이비인후과학회지

Ectopic thyroid is an uncommon embryological aberration characterized by the presence of thyroid tissue in a site other than in its usual pretracheal region. It occurs along the path of descent of the developing thyroid primodium from the foramen cecum. It most commonly presents as a lingual thyroid, and is the only thyroid in 70% of all cases. It is extremely rare for two ectopic foci of thyroid tissue to present simultaneously. The authors report a recent case of dual ectopic thyroid present in the lingual and infrahyoid area with no thyroid tissue in the pretracheal area in a 15 year-old girl. The presence of dual ectopic thyroid tissue was confirmed by CT and scintigram with 99 mTc. The patient had originally been scheduled for surgery under the impression of a thyroglossal duct cyst, but the pre-operative neck CT and thyroid scans revealed the presence of a dual ectopic thyroid, thus preventing unnecessary surgery. Therefore, ultrasound scans or a neck CT's and thyroid scans should be performed routinely to confirm the presence of thyroid in the normal position and avoid unnecessary surgeries.