[A thyroglossal duct cyst with ectopic thyroid carcinoma].

An asymptomatic swelling in the neck of a 15-year-old boy, was revealed after resection to be due to a papillary thyroid carcinoma. He was treated with a near-total thyroidectomy, radiotherapy at an ablation dosage due to a scintigraphically demonstrated remnant thyroid tissue, and thyroid hormone supplement. Almost 2 years after the tumour resection, a recurrent carcinoma was found in the neck. Prior to the resection of symptomatic thyroglossal duct cysts, it should be ascertained whether nodular thyroid abnormalities are present. In about 1% of resected thyroglossal duct cysts a carcinoma is found, most often of the papillary type. In 10-40% of the patients who undergo a subsequent thyroidectomy, malignant focuses are also found in the thyroid. In view of this multifocal occurrence and the fact that in most cases the diagnosis of carcinoma is only made after the operation, which often implies uncertainty about oncological radicalness, the authors advice to perform a (near-)total thyroidectomy as the standard procedure in case of thyroglossal duct carcinoma. After this adequate treatment with 131I should be given. A more limited approach seems only warranted when radicalness is certain and indications for nodular thyroid disease are absent.