[Thyroid nodules - how to proceed?].

Ultrasonic examination of the thyroid is essential in any diagnostic process on the thyroid. It helps to meet the challenge of identifying the few malignant among the thousands of benign nodules. Besides tumour infiltration in surrounding tissue and lymph node metastases - which may prove thyroid cancer - there are well-established criteria suggesting malignancy. A safe distinction between benign and malignant nodules however is not possible by ultrasound alone, nor can hormone producing adenoma be discriminated from inactive nodules. Scintigraphy is helpful in identifying autonomous adenoma but is of no use in assessing the risk of malignancy of thyroid nodules. Ultrasound guided thyroid fine needle aspiration (FNA) is a safe method to prove malignancy. In selected cases, ultrasound guided therapies like percutaneous ethanol instillation (PEI) is an effective treatment of autonomous thyroid ademona.