Triple Ectopic Thyroid Gland in a 4-Year-Old Child

Triple ectopic thyroid is exceedingly rare. The objective of this report is to present a case of triple ectopic thyroid that presented as a right submandibular mass in a euthyroid child.

A 4-year-old boy presented with a right-sided neck mass for 2 months. Neck ultrasound revealed a soft tissue mass adjacent to the submandibular salivary gland. Post intravenous contrast computed tomography scan, an additional 2 enhancing nodules were identified in the sublingual and hyoid areas. No thyroid tissue was identified in its normal pretracheal region. A fine-needle aspiration biopsy under ultrasound guidance of the right neck mass revealed numerous follicular epithelial cells in a background of homogenous colloid, characteristic of normal thyroid tissue. A Tc-99m pertechnetate thyroid scan demonstrated that the other 2 nodules were also ectopic thyroid tissue. Further workup revealed a thyroid stimulating hormone of 6.19 mIU/L (0.7-6.4) and a free thyroxine level of 1.0 ng/dL (0.8-2.0).

Delayed presentation of ectopic thyroid tissue as a mass presents diagnostic challenges, particularly when it is not found around the course of the thyroglossal duct and is associated with 2 additional ectopic thyroid nodules. Very few cases of triple thyroid ectopy have been reported particularly in pediatric patients.

Although most cases of ectopic thyroid in children are identified shortly after birth, a late presentation can occur. In a euthyroid patient presenting with a mass and absence of a thyroid gland in the normal position, thyroid ectopy should be included in the differential diagnosis.