[Diagnostic work-up of euthyroid nodules: which nodules should undergo fine-needle aspiration biopsy? Relevance of ultrasound].

Efficient and rational methods for the differential diagnosis and decision are required to identify those nodules with an increased carcinoma risk or those which are hot among the many thyroid nodules. History, ultrasound and TSH- and CT-determination do allow a risk assessment for the further diagnostic work up. Especially ultrasound criteria for malignancy lead to a risk stratification and efficient selection of thyroid nodules for Fine needle aspiration biopsy (FNAB). FNAB is the diagnostic method with the best sensitivity and specificity for the distinction between benign and malignant thyroid nodules. However, the efficiency of the fine needle aspiration biopsy requires sufficient training and experience of both the cytopathologist and the person performing the fine needle aspiration biopsy. Thyroid nodules with a suspicion for malignancy should be referred to the surgeon. Euthyroid thyroid nodules with lack of clinical, ultrasound or cytologic criteria for malignancy and normal calcitonin should be followed up.