Endocrine Abstracts

Introduction: Thyroglossal duct carcinoma (TDCCa) is a very rare finding and its presentation is similar to a benign cyst. Carcinoma arising in this tract is uncommon. It is still debated whetherTDCCa originates from the thyroid gland, from the thyroglossalduct it self (de novo theory) or from both. Although the differentiation may be difficult, this distinction can play a crucial role in treatment decisions regarding the inclusion of thyroidectomy as part of the treatment.

Case reports: We report three cases of concomitant papillary duct carcinoma in the thyroglossal duct cyst and thyroid gland.The mean age was 68 years with a male:female ratio of 2:1. There was no medical history was for thyroid gland or neoplastic diseases. A rapid enlargement of the mass and dysphagia was reported in two cases. Physical examination revealed a painless well-demarcated mass localized in the midline of the neck above the thyroid gland in all cases. The thyroid gland was apparently normal and no significant cervical lymphadenopathy was found. Thyroid function tests were normal. The neck ultrasound and CT scan revealed a pattern suggestive of a malignant thyroglossal duct cyst in two cases. A Sistrunk intervention associated with total thyroidectomy and central neck dissection was performed. Histopathological examination of the specimen revealed papillary carcinoma arising in the TGDC and papillary microcarcinoma of the thyroid gland without extrathyroidal extension and without metastasis in central neck lymph nodes. Surgical procedures were followed by iodine scan and radioactive iodine therapy with 131I ablation. Thyroid hormone replacement therapy was given regularly.

Conclusion: We present three rare cases of synchronous papillary carcinomas appeared in thyroglossal duct cysts and thyroid gland.These cases highlight that thyroglossal duct cyst can serve as malignancy of thyroid gland. Surgeons must be aware and include this entity while examining a patient with a neck mass located around hyoid bone with physical examination suspected malignancy. Considering the embryological development of the thyroid, the ideal treatment consists in the sistunk intervention associated with total thyroidectomy and central lymph nodes dissection.