Hypertrophied thyroid tissue in a thyroglossal duct remnant

A 37-year-old woman was evaluated for a neck mass. This was located in the midline below the hyoid bone. Thirty-three years had elapsed since she had undergone subtotal thyroidectomy for hyperthyroidism. Eight years prior to examination, the patient had discontinued her thyroid maintenance medications. She had discovered the mass eight months prior to examination. Thyroid scan (Fig. 1) showed intense uptake in the mass. At operation the mass was attached to the midportion of the hyoid bone by a small fibrous band, as is usual in a thyroglossal duct remnant. Biopsy results showed diffuse thyroid hyperplasia. Thyroglossal duct remnants are known to harbor cysts or thyroid carcinoma, but growths of compensatory hyperplastic tissue are unusual.