Clinical data: a 73-year-old woman was referred for a follow-up examination. She was operated on a Hürthle-cell cancer 5 years earlier. Total thyroidectomy and external irradiation were performed because the lack of radioiodine uptake. The thyroglobulin-level remained elevated and was in the range of 8-13 ng/mL without any tendency in the past years.

Palpation: a firm lesion in the right thyroid bed.

Functional state: subclinical hyperthyroidism on daily 175 microgram levo-tiroxine.

Results of blood test: TSH 0.07 mIU/L, FT4 21.8 pM/L, serum-thyroglobulin 11 ng/mL, anti-hTG below 20 U/mL.

Ultrasonography: there was a hypoechogenic, inhomogeneous mass with irregular borders in the right thyroid bed. The vascularization was practically absent.

Cytological diagnosis: recurrent oxyphilic cell carcinoma of the thyroid.

On CT scan two lymph nodes were detected in the right side of the neck.

Histopathology: metastasis of oxyphilic cell carcinoma of the thyroid  to the lymph nodes in the neck.

6 months later the thyroglobuline level was unchanged. On PET examination, no suspicious lesion was found.

The patient was followed-up for another 3 years, when she died of pulmonary embolism.