Clinical data: A 42-year-old woman noticed a lump in the right thyroid a week ago.

Palpation: a firm nodule in the right thyroid.

Result of blood test: euthyroidism (TSH-level 2.57 mIU/L).

Ultrasonography: The thyroid was echonormal. There was a hypoechogenic nodule with intranodular fibrosis in the right thyroid. The nodule displayed halo sign and both perinodular and intranodular blood flow.

Cytological diagnosis: follicular tumor.

Histopathological diagnosis: microfollicular adenoma.