Clinical presentation: A 36-year-old woman requested a second opinion. She has borne for three months. Several weeks later she noticed a goiter and signs of hyperthyroidism.
Six weeks after delivery on evaluation in another hospital a hyperthyroidism (TSH 0.01 mIU/L, FT4 32.7 pM/L) and a suspicious nodule in the right lobe were detected. Aspiration cytology resulted in atypia of unknown significance. (On the cytological report heterogeneous lymphoid elements were described with clusters of oxyphilic cells presenting significant enlargement.) She was told that she has to cease breastfeeding, and daily 50 mg propylthiouracil was administered. Surgery was planned in euthyroid state.
The patient did not accept the suggestion and continued breastfeeding and took no medication. The patient visited us 7 weeks after this examination.

Palpation: Both lobes were firm.

Hormonal investigation: subclinical hyperthyroidism (TSH 5.18 mIU/L, FT4 11.7 pM/l, aTPO 954 U/mL).

Ultrasonography. Both lobes were minimally-moderately hypoechogenic and contained numerous more hypoechogenic areas ranging from 2 to 28 mm. None of these areas corresponded to a nodule in a pathological sense, their shape was not regular geometrical and they had an irregular border. The vascularization was increased.

We told the patient that she did not harbor any nodule and does not require surgery. She asked me to make cytology. Cytology revealed Hashimoto's thyroiditis.

We suggested follow-up without any medication.

Three months later the laboratory test showed subclinical hypothyroidism while another 6 months later the patient became euthyroid.

Comments.

1. The patient had a classical form of post partum thyroiditis. Except for severe forms, the hyperthyroid phase does not require thyrostatic drug because by administering it we are not able to accelerate the heal of hyperthyroidism but we can make the subsequent hypothyroid phase more severe. To stop breastfeeding is also not acceptable in usual cases.

2. The ultrasound presentation is unequivocal, this patient has no nodule in a pathological sense, therefore she cannot harbor carcinoma.

3. Both the thyroiditis and the dysfunction used to cause atypia, even of severe degree. The overinterpretation of these signs should be avoided in the event of an underlying thyroiditis.