Clinical presentation: A 73-year-old man was referred for evaluation of a nodule discovered on screening.

Palpation: There was a not firm nodule in the right lobe.

Ultrasonography revealed a moderately hypoechogenic thyroid. There was an echonormal nodule in the ventral part of the right lobe.

Aspiration cytology resulted in benign colloid goiter.

Hormonal investigation: subclinical hypothyroidism (TSH 6.01 mIU/L, FT4 12.8 pM/l, aTPO 447 U/mL).

Suggestion: TSH determination in a year, ultrasound in three years.

Summary of follow-up. The TSH-levels of the patient were 2.07 mIU/L, 4.08 mIU/l, 5.19 mIU/L, 2.00 mIU/L, 6 months, 1 year, 2 years, 3 years after the initial examination, respectively.

Comment. In the event of a subclinical hypothyroidism, we usually suggest a replacement therapy if the TSH exceeds 5 to 6 mIU/L at two subsequent checks except for woman in childbearing age and for patients whose thyroid is enlarged.