Clinical data: A 21-year-old woman was referred for evaluation of elevated TSH-level detected on evaluation of fatigue.

Palpation: Both thyroids were moderately firm.

Result of blood tests: subclinical hypothyroidism (TSH 4.19 mIU/L, FT4 13.8).

Ultrasonography: The thyroids were moderately hypoechogenic. There was a small nodule in the ventral part of the right lobe. It was hypoechogenic and presented microcalcifications. The vascularization was not specific.

Aspiration cytology was performed from the nodule. Monolayered sheets predominated the smear, microfollicles were found, too. A few nuclei contained inclusions and grooves. The pattern itself was not sufficient to raise the suspicion of malignancy.

Taking the ultrasound presentation into account we gave a common ultrasound-cytological diagnosis of suspicion of papillary carcinoma and Hashimoto's thyroiditis.

Total thyroidectomy was performed. Histopathology disclosed Hashimoto's thyroiditis and follicular carcinoma with a maximal diameter of 3 mm according to the nodule. The tumor spread extracapsular.

Comments.

1. To judge the presence of halo and perinodular blood flow is difficult in the event of a small lesion.

2. We presented the cytological smear in a postgraduate course. The opinion of experienced thyroid cytopathologist were divided almost equal as to whether the pattern is benign or belongs to atypia of undetermined significance or is suspicious for malignancy.

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