Clinical presentation: A 53-yr-old woman came to follow-up examination. She has been diagnosed with an autonomously functioning nodule for 7 years. TSH level was always in the normal range.

Palpation: a firm nodule in the medial part of the left lobe.

Laboratory test: TSH 1.05 mIU/L.

Ultrasonography. The thyroid was echonormal. There was a hypoechoic nodule in the lower, isthmic part of the left lobe. The nodule had ill-defined borders in more than the half of the circumference of the nodule. Moreover, the nodule was suspicious having lobulated margins, as well. Compared with the previous examination, the nodule has increased in size.

Cytology resulted in benign lesion with signs of hyperfunction.

Comment. Obviously, an autonomously functioning nodule is not target of cytology. Nevertheless, in certain cases, cytology might be indicated. In this patient, there were several circumstances, which raised suspicion. The least important was that the nodule had increased in size. The firm consistency and the ultrasound abnormalities which were not described on previous reports were more important.