[Clinical aspects and preoperative diagnosis in differentiated thyroid gland carcinoma].

Etiologic factors such as iodine deficiency and exposure to ionizing radiation especially during childhood are determinants of histological type and malignancy of differentiated thyroid carcinomas. The rarely occurring anaplastic thyroid carcinoma represents a highly malignant tumour of old patients, causing local compression symptoms at an early stage of disorder. Since early symptoms are lacking, sensitivity and specificity of further diagnostic approaches are of particular importance in the care of differentiated thyroid carcinomas. Obligatory procedures at the preoperative stage are ultrasound, scintigraphy, determinations of thyroid hormones and calcium on serum as well as an otolaryngological investigation. The preoperative determination of calcitonin may assist in the differential diagnosis of a cold nodule and in the detection of a medullary thyroid carcinoma. Measurements of thyroglobulin are helpful only for the follow-up of patients with differentiated carcinomas. The highest degree of specificity and sensitivity is achieved by fine-needle aspiration. Finally, if clinical suspicion of malignancy exists, surgical intervention should be performed even if the result of cytological analysis was negative. Whether the color Doppler energy ultrasound provides valuable additional informations especially in the differential diagnosis of thyroid nodules during childhood, is still undecided.