Thyroglossal Duct Cyst Carcinomas in Pediatric Patients: Report of Two Cases with a Comprehensive Literature Review.

Thyroglossal duct cyst (TGDC) carcinomas are rarely encountered in the pediatric population. The clinical behavior of these tumors in the pediatric setting is unclear and management is not well defined. Two cases of pediatric thyroglossal duct cyst carcinoma were identified in a review of all thyroglossal duct cysts diagnosed over a ten year period. These two cases were analyzed along with 57 cases of thyroglossal duct cyst carcinoma affecting patients less than 21 years of age compiled from the English literature. Fifty-nine patients (36 females, 23 males) aged 6-20 years (mean 15.0 years) were identified. All presented with an anterior midline neck mass, which was typically mobile and non-tender. The average tumor size was 2.6 cm. Histologically, all tumors were papillary thyroid carcinomas arising in a background of a thyroglossal duct cyst. The tumors exhibited a papillary, follicular, or mixed architecture with classical papillary thyroid carcinoma nuclear features. Soft tissue extension was present in 16 cases. All patients were managed surgically with a Sistrunk procedure, with additional thyroidectomy performed in 29 patients, combined with a lymph node dissection (n = 15), or a Sistrunk and lymph node dissection (n = 5). All patients were stage I at presentation, with 11 showing lymph node metastases. Postoperative radioactive iodine was employed in 20 patients. A papillary carcinoma of the thyroid gland was reported in four of the patients who had concurrent/subsequent thyroidectomies. Recurrences were reported in four patients, with distant metastases in one patient, who died of disease (13 months). Follow up data was available for 45 patients, with an overall mean follow-up of 54.5 months. All patients were alive, with the exception of one who died with disease. TGDC carcinomas in pediatric patients is associated with a good overall prognosis, best managed by Sistrunk procedure alone, with selected lymph node dissection if clinically indicated.