[Thyroid nodules: The Guidelines of the American Thyroid Association from a European Perspective].

In Germany and in other regions with former iodine deficiency, thyroid nodules and nodular goiter are still much more frequent than in the U.S.A. The American Thyroid Association (ATA) has published 2015 revised guidelines for patients with thyroid nodules and differentiated thyroid cancer. For evaluation of suspected thyroid nodules the authors describe high, intermediate, low and very low suspicion pattern and recommend further fine needle aspiration cytology, depending on the pattern and the size of the nodule. The high suspicion pattern includes irregular margins of the nodule, which may be an important criterion for malignancy of solitary nodules. In nodular goiters with multiple nodules grown together and without clear margins, frequently observed in former iodine deficiency regions, irregular margins may not be a significant criterion for malignancy. Another pattern, hypoechogenicity, which is frequently seen in benign nodules in former iodine deficiency areas, is also not a clear criterion for malignancy. Only strong hypoechogenicity may indicate malignancy. Another difference relates to the recommendation of scintigraphy that according to the guideline is restricted to patients with decreased TSH. In regions with former iodine deficiency, it has been demonstrated that thyroid autonomy may be present even if TSH is in the lower normal range. Therefore, in Germany scintigraphy is recommended for preoperative evaluation of all patients with thyroid nodules or nodular goiter.