Thyroglossal duct cysts can contain ectopic thyroid tissue, and in some cases this tissue may be the only functional thyroid gland. We present a 6-year-old girl with delayed diagnosis of iatrogenic hypothyroidism that developed following excision of a thyroglossal duct cyst.

Is a thyroglossal duct cyst on the thyroid?

A thyroglossal duct cyst is a mass or lump in the front part of neck that is filled with fluid. While a baby is developing in the womb, the thyroid gland begins at the base of the tongue. Before birth the thyroid gland moves in the neck to its usual position below the thyroid cartilage and above the sternum.

Can a thyroglossal cyst be cancerous?

The presence of malignancy occurring in a thyroglossal duct cyst is a rare condition, accounting only for 1% of all cases of thyroglossal duct cyst. This report is of a rare case of papillary carcinoma arising in a thyroglossal duct cyst and includes a review of the literature.