Synchronous occurrence of papillary carcinoma in the thyroid gland and thyroglossal duct in an adolescent with congenital hypothyroidism.

Thyroid carcinoma (TC) combined with congenital hypothyroidism is rare. The synchronous occurrence of these two conditions is even rarer. We describe a patient with congenital hypothyroidism in whom hyperthyroglobulinemia and nodules developed despite adequate replacement therapy. Papillary TC was detected at age 19 years. Postoperative diagnostic scintigraphy showed increased uptake in the thyroglossal duct region. Repetitive imaging of the thyroid gland can be useful in the early detection of TC in patients with congenital hypothyroidism. Moreover, this rare situation can be complicated by a synchronous thyroglossal duct carcinoma. Thyroglossal duct carcinoma can be detected if diagnostic scintigraphy is performed after total thyroidectomy.