Clinical presentation: A 69-year-old woman was referred for aspiration cytology. Hypothyroidism was discovered on routine blood test.

Palpation: Both lobes were firm while the left thyroid was nodular, too.

Functional state: hypothyroidism (TSH 9.79 mIU/L, anti-TPO 596 U/mL).

Ultrasonography. The thyroid was moderately hypoechogenic. The right lobe presented micronodular form while the left lobe contained a relatively large lesion composed of multiple nodules. The lesion displayed perinodular blood flow.

Cytology of the lesion in the left lobe resulted in benign follicular proliferation.

Final diagnosis: primary hypothyroidism caused by Hashimoto's thyroiditis. Benign nodular goiter.