Follicular thyroid carcinoma in a hyperfunctioning thyroid nodule with suspicious sonomorphological features

Thyroid nodules are a frequent and often incidental finding in up to 47 % of the German or up to 72 % of the US-population. Because of risk for malignancy every thyroid nodule should be classified. Since most nodules are detected by ultrasound, evaluation of sonomorphological features is usually the first step to assess risk of malignancy. Further diagnostic steps may comprise thyroid scanning (with 99mTechnetium-Pertechnetat (99mTcO4) or 123I), fine needle aspiration biopsy (FNAB) and laboratory tests (calcitonin) [1]. Due to the wide acceptance of the thyroid imaging reporting and data system (TIRADS) established by Kwak et al. [2] in 2011 or modified systems, the indication to perform scintigraphy or FNAP has become more restricted e. g. to patients with documented hyperthyroidism as published by the recent ATA recommendation about the use of scintigraphy [1]. On the other hand thyroid scintigraphy may also be useful in euthyroidism to identify nodules with increased uptake, which widely rules out malignancy.