A cadaveric case report of dual thyroid: ectopic and normal location thyroid with brief review of literature

Abstract

Ectopic thyroid tissue is a rare congenital anomaly due to developmental defect in thyroid gland. Ectopic, accessory, or aberrant thyroid refers to the presence of thyroid tissue in locations other than normal pretracheal position in the anterior neck region. The thyroid dysgenesis occurs due to abnormal organogenesis of the thyroid gland leading to morphological variations, such as hypoplasia, hemiagenesis, and agenesis with ectopic thyroid being the most common form of thyroid dysgenesis. Here, we are presenting a case of dual thyroid in the form of ectopic or accessory thyroid tissue along with normal location thyroid found during a routine dissection of a female cadaveric body. The ectopic thyroid tissue was seen as an oval structure about 2.2 cm x 1.6cm x 1.0 cm, situated in the midline near the hyoid bone. It was located 10.2 cm superior to a normally located thyroid gland and consistent with the track of the thyroglossal duct. The ectopic thyroid tissue could be asymptomatic or it could present with any disorder affecting the main thyroid gland including malignancy. The significance of this cadaveric case report and a brief review of the literature on normal location thyroid gland and ectopic thyroid highlight an uncommon but potentially important congenital anomaly that can be a source of diagnostic confusion and a challenge for therapeutic management.

Introductory Chapter: Knowledges on Thyroid Cancer

“…Superior and middle veins of the thyroid gland drain into the internal jugular vein; the inferior vein of the gland drains into the brachiocephalic vein or directly into the superior vena cava [2,3].…”