Clinical data: a 36-year-old woman was sent for an evaluation of a thyroid nodule discovered incidentally.

Functional state: euthyroidism (TSH-level 1.41 mIU/L).

Palpation: no abnormality.

Ultrasonography: a hypoechogenic nodule can be seen in the right lobe without a halo sign, but with perinodular blood flow.

Cytological picture: there was no colloid on the smear. There were thyrocytes located in atypical microfollicles with nuclear crowding. Follicular cells were enlarged but did not display pleomorphism.

Cytological diagnosis: follicular tumor with higher than the average risk for carcinoma.

Histopatholog: follicular cancer - minimally invasive type.