Papillary carcinoma arising from de novo ectopic thyroid tissue within thyroglossal duct cyst: A rare case report

Abstract

The most common congenital anomaly of thyroglossal duct is a thyroglossal duct cyst, but carcinoma arising from a thyroglossal duct cyst is a rare phenomenon. Carcinomas involving thyroglossal duct cysts are mostly papillary carcinomas. Definitive diagnosis of carcinomas involving thyroglossal duct cysts is done through surgical excision and subsequent histopathological examination. Most carcinomas arise de novo from ectopic thyroid tissue within thyroglossal duct cysts, but the direct spread of papillary carcinomas arising from the thyroid gland can also present themselves as carcinomas involving thyroglossal duct cysts in a minority of patients. Clinical presentation in most of the patients with carcinoma of thyroglossal duct cyst is quite similar to that of the patients with histopathologically diagnosed thyroglossal duct cyst, i.e., a painless anterior midline neck swelling with cosmetic concern and no other significant symptom(s). Careful clinical examination, imaging techniques, fine needle aspiration cytology, etc., can be helpful in indicating the presence of carcinoma preoperatively. Management of patients with thyroglossal duct cyst carcinoma involves only the Sistrunk procedure in the majority of cases. However, in a minority of patients, management by Sis trunk procedure with additional total thyroidectomy (with or without dissection of lymph nodes of the neck) and adjuvant chemo and radio-ablation therapies are needed. Here, we report a case of a 17-year-old female with papillary carcinoma involving thyroglossal duct cyst who presented with a submental swelling and was eventually managed by Sis trunk procedure, total thyroidectomy, and adjuvant therapies for optical cure. Decisions for the management of her cancer were taken through multidisciplinary interactions at tumor board meetings and by judging her surgical and therapeutic needs based on her clinical, radiological, and pathological findings.