[Differentiated thyroid carcinoma--essential for the practitioner]

Differentiated thyroid carcinoma (DCT) is a rare carcinoma (incidence 8-12/100,000) with an excellent prognosis (five year survival of papillary thyroid carcinoma 95%). The presenting symptom of DCT is most frequently an indolent thyroid nodule, often discovered by chance at the occasion of a routine clinical examination. Rarely, DCT presents with a fixed ipsilateral cervical lymph node enlargement or a newly developed hoarseness of the voice. Patients at risk are those who have had irradiation of the head or neck, those with rapid enlargement of a thyroid nodule or patients with rare familiar tumour syndromes. Treatment is most frequently accomplished with total thyroidectomy followed by radioiodine ablation with or without suppressive levothyroxine therapy. In special situations, several radioiodine therapies are needed. All patients need regular long term follow up by neck sonography, measurements of thyroglobuline levels and control of thyroid hormone replacement therapy. DCT may relapse many years (>10) after initial therapy. Patients should ideally be followed by specialized interdisclipinary centres.