Papillary thyroid carcinoma identified after Sistrunk procedure: report of two cases and review of the literature.

Thyroglossal duct cysts represent the most common congenital cervical malformations. Carcinomas arising in the thyroglossal duct cysts are rare neoplasms characterized by a relatively non aggressive behavior with rare lymph node spread. Approximately 1% of thyroglossal cysts contain a carcinoma. The most frequent histological type is papillary carcinoma, accounting for about 80% of cases. Currently, most authors agree about their primary origin ex novo from ectopic thyroid tissue in the cyst. In most cases the diagnosis of thyroglossal duct carcinoma (TDC) is not made until histopathological examination has been performed on a resected cyst without any suspected clinical sign of malignancy. The definition of the correct surgical treatment for these carcinomas is still controversial; most authors maintain that resection of a TDC with the Sistrunk procedure can be considered oncologically adequate when dealing with a differentiated carcinoma without extracapsular invasion and/or lymph node metastases and with a normal thyroid. We present two cases of papillary thyroid carcinoma identified after resection of a thyroglossal cyst according to the Sistrunk procedure and managed with different surgical approaches according to the different sites of the tumors. In addition, we discuss appropriate therapeutic strategies in light of the most recent data in the literature.