Clinical data: A 42-year-old man was referred for evaluation of a thyroid nodule detected on examination performed because of ventricular arrhythmia.

Palpation: The right lobe was very enlarged, and not freely moveable.

Functional state: euthyroidism (TSH 2.11 mIU/L).

Ultrasonography. The right thyroid was composed of a large hypoechogenic nodule. The vascularization was not specific. The left lobe was inhomogeneous.

Cytology resulted in carcinoma - either a less well-differentiated variant of papillary cancer or poorly differentiated inzular carcinoma.

Histopathology disclosed papillary carcinoma with less well-differentiated foci.