Clinical data: A 62-year-old woman requested a second opinion. She has noticed a lump in the right side of the neck for three months. On evaluation a moderate degree of hyperthyroidism was detected. The nodule did not take up radioiodine. TSAb and anti-TPO resulted in normal level. Cytology was not diagnostic and surgery was advised.

Palpation: The right lobe was firm and nodular.

Functional state: subclinical hyperthyroidism on daily 15 mg methimazole: TSH 0.13 mIU/L, FT4 11.6 pM/l, FT3 4.07 pM/l.

Ultrasonography. A large hypoechogenic nodule occupied almost the entire right lobe. The nodule presented an incomplete halo and signs of perinodular blood flow. The left thyroid was moderately hypoechogenic and inhomogeneous and contained several relatively small nodules with different echogenicities in the range of 5-15 mm.

An all three attempts of FNA bloody material was gained and there was no thyroid cell on the smears.

Surgery was advised.

Histopathology disclosed papillary carcinoma corresponding to the nodule in the right lobe. More than 90% of the lesion was necrotized and a focus of papillary carcinoma with a maximal diameter of 15 mm was found at the edge of the lesion. The remaining nodules proved to be hyperplastic.

Comment. Although almost the entire lobe was composed of the nodule, the nodule was surrounded with a small normal parenchyma almost all along except for the dorsomedial part of the nodule. Histopathology disclosed that the tumor reached the capsule of the thyroid but has not broken through.