Clinical data: a 63-year-old man was referred for evaluation of a thyroid nodule which was discovered on follow-up examination of a malignant melanoma. The tumor was located in the forearm. Interferon therapy was administered for 3 years. Hypothyroidism has developed six months after initiating the therapy.

Palpation: a not firm nodule in the left lobe.

Functional state: euthyroidism on daily 62.5 microgram levo-tiroxine (TSH 2.96 mIU/L).

The lesion in question is located in the left lobe.