Clinical data: a 69-year-old woman came to a regular follow-up investigation. We examined her 5 years earlier when she had a nodule with the dimensions of 8x8x13 mm. FNAC was performed and it gave a benign result. She had no complaints.

Palpation: a moderately firm nodule in the right lobe was palpable.

Results of blood tests: euthyroidism (TSH-level 1.05 mIU/L).

Ultrasonography: the thyroid was echonormal. A moderately hyperechogenic, inhomogeneous nodule was present in the right lobe with the dimensions of 10x11x13 mm. It means that the volume of the nodule increased from 0.4 ml to 0.75 ml in 5 years. The nodule presented increased intranodular blood flow.

Cytological picture. There was no no colloid in the background. A few atypical clusters were present. A great proportion of follicular cells exhibited nuclear groove, a few cells did inclusion.

Clinical-cytological diagnosis: papillary carcinoma.

Histopathology: multifocal papillary carcinoma.

Comment: we reexamined the original smears gained 5 years earlier. There were only a few cells on the smear without any atypia. The correct diagnosis would be not diagnostic.