Clinical presentation: a 56-year-old woman was referred for an evaluation of a nodule discovered by screening.

Palpation: a not firm nodule in the left lobe.

Hormonal examination: indicated euthyroidism with TSH 2.19 mIU/L.

Ultrasonography. The thyroid was echonormal and contained hypoechogenic areas. The echogenicity index was 20%. There was an echonormal nodule in the left lobe. The lesions displayed halo sign and perinodular blood flow.

Cytology was performed and corresponded to a follicular tumor.

A combined clinical-ultrasound-cytological diagnosis was Hashimoto's thyroiditis and follicular proliferation with less than 1% risk of carcinoma.

Follow-up was advised with yearly ultrasound and TSH determination.

Comment.

1. The cytology is remarkable. Degenerative changes may cause irregular chromatin figures resembling groove. A typical groove is straight and starts at one side of the nucleus.

2. The risk of malignancy is very low in the event of an echonormal nodule. Combining the results of cytology and ultrasound, the risk of a follicular carcinoma is negligible in this patient.