Clinical presentation: A 48-year-old woman was referred for evaluation of a nodule discovered by her GP on routine examination performed because of upper airways infection.

Palpation: a large nodule in the right lobe.

Hormonal examination indicated euthyroidism with TSH 1.16 mIU/L.

Ultrasonography revealed a solitary echonormal-minimally hypoechogenic nodule with halo sign and perinodular blood flow in the right thyroid.

Combined ultrasound-cytological report: follicular tumor with less than the average risk for malignancy.

Histopathology disclosed a minimally invasive follicular cancer.

Comment. There were only a few follicles on the smear. Taken the sonographic picture into account, the cytological diagnosis was not difficult: a relatively large solitary nodule showing halo sign is very likely a follicular tumor.