Clinical presentation: A 35-yr-old woman was referred for evaluation of a nodular goiter. The lesion was discovered on screening.

Palpation: a moderately firm nodule in the right lobe.

Laboratory tests: TSH 0.85 mIU/L, aTP0 0,7 U/mL.

Ultrasonography. The thyroid was echonormal. There was a heterogeneous, dominantly hypoechoic lesion in the central part of the right lobe. The lesion had undulated surface. The issue is whether the lesion corresponds to a single nodule or is composed of distinct lesions. In the former, the borders are pathologically lobulated, while in the latter the undulation is of non-pathological cause.

Cytology resulted in benign colloid goiter.

Comment. The interpretation of the mass as a solitary nodule or not decides the judgement of nodule' borders. Nevertheless, cytology is indicated in both cases.