[Papillary carcinoma arising in thyroglossal duct cyst: a case report and review of the literature].

While thyroglossal duct cysts are a frequent cause of cervical masses, carcinomas arising in thyroglossal duct remnants are rare. In this paper the Authors report a new case, which occurred in a young woman. The diagnosis of carcinomas in thyroglossal duct cysts almost always comes as a surprise upon pathologic examination. The type of neoplasia most frequently described in Literature is that of the papillary carcinoma (82%). Other types of carcinomas are also reported in Literature: mixed follicular-papillary carcinomas (9 cases), squamous cell carcinomas (10 cases) and follicular carcinomas (3 cases). There are different theories regarding the origin of and therapy for these malignancies. In the sixties some Authors thought that these carcinomas were metastases of thyroid carcinomas. Now, following demonstration of normal thyroid tissue occurrence in the wall of thyroglossal duct cysts, it is almost universally accepted that a carcinoma may arise from thyroglossal remnants. The foci of cancer found in the thyroid reported only infrequently in Literature are a result of the plurifocality of papillary carcinoma. The Authors suggest that the Sistrunk procedure is an adequate, sufficient treatment if the carcinoma is limited to the cyst's walls. They also recommend postoperative administration of substitution therapy of thyroid hormones. Indications for thyroidectomy are then discussed.