Hence, a total thyroidectomy was performed. The histologic report was papillary carcinoma of the thyroglossal duct cyst with invasion to the cyst wall and papillary carcinoma of the thyroid gland ...

Conclusions: The thyroglossal duct cyst must be studied in the adult population through fine-needle aspiration biopsy (FNAB) and a frozen section in cases in which FNAB is inconclusive or unavailable.

Your daughter's cyst sounds like a thyroglossal duct cyst. This is a defect which is present from birth but does not show itself until later in childhood, most commonly in preschools aged children ...