Endocrine Abstracts

Thyroglossal ductal cyst is the most common congenital cervical pathology. Abnormalities in the embryologic development and migration of the thyroid gland can result in this ectopic thyroid tissue, which may occur in the midline in any position from the base of the tongue to the mediastinum. They are rarely seen in adults. Malignant transformation of the cyst is quite rare and is encountered mostly in adults.

We retrospectively reviewed two cases of thyroglossal duct carcinoma diagnosed in the central hospital of the army of Algiers from 1990 to 2008. The two patients are females, a 64 and 43 year-old with ectopic thyroid tissue in the mediastinum associated to a multinodular goiter. A surgical excision plus thyroidectomy was performed and histology showed in one case a follicular carcinoma and in the other a papillary carcinoma. The ectopic thyroid tissue was clearly separate from the thyroid gland and there was not malignant tissue in the thyroid gland. Prophylactic radioactive iodine treatment was done. The two patients are still in follow-up and no pathology was detected 3 years later.

This type of carcinoma is usually an incidental finding and has a good prognosis, with only rare instances of metastasis close follow-up is need for recurrence and distal metastasis may be possible.