Clinical presentation: 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. There was a hypoechogenic nodule in the right lobe. The lesion had no halo but showed 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.

Histopathology disclosed minimally invasive follicular cancer.