Clinical data: a 39-year-old woman was referred for aspiration cytology. A nodule was detected on a routine examination. She had no complaints.

Palpation: a firm nodule in the left lobe.

Result of blood tests: euthyroidism (TSH-level 1.48 mIU/L).

Ultrasonography: the thyroids were echonormal. There was a large hypoechogenic nodule occupying almost the entire left lobe. The nodule displayed a halo sign and both perinodular and intranodular blood flow.

Cytology: resulted in follicular tumor.

Histopathology: disclosed follicular adenoma.