Clinical presentation: A 41-year-old woman came to a follow-up examination. She has been treated for hyperthyroidism for three months. She became allergic both to methimazole and to propylthiouracil.

Palpation: no abnormality.

Functional state: hyperthyroidism (TSH 0.001 mIU/L, FT4 48.2 pM/L).

Ultrasonography. The thyroid was minimally hypoechogenic and had several more hypoechogenic areas. One of the latter located in the ventral part of the right lobe had blurred borders and an ambiguous echogenic figure. The vascularization of the thyroid was extremely increased.

Cytology resulted in benign hormonal atypia.

Lugol's solution was used to control hyperthyroidism and thereafter a total thyroidectomy was performed. Histopathology disclosed diffuse goiter.

Comments.

1. There is a paradoxical situation regarding the lesion in the ventral part of the right lobe: although this area was with great probability not a nodule in a pathological sense, we had to perform FNAC because of the presentation of the lesion. This is not a rare situation in autoimmune thyroid diseases which usually presents more hypoechogenic and not well demarcated areas.

2. We regularly use the Lugol's solution for controlling hyperthyroidism in patients who became allergic to all thyrostatics. I personally treated more than 50 patients in this situation. We give increasing amount of Lugol's solution: 3x3, 3x5, 3x7, 3x9, 3x10, 3x11, 3x12, 3x13 drops. At this time, we check the FT4 and FT3 levels which used be normal, and the subsequent day the patients are operated on. If we have to postpone the surgery for any reasons than we have to decrease the dose of the Lugol's solution in a reverse order to avoid serious thyrotoxicosis.