Clinical presentation: A 50-year-old woman was referred for evaluation of a nodular goiter and a newly diagnosed hypothyroidism. She has had complaints suggesting hypothyroidism and her GP initiated the evaluation.

Palpation: no abnormality.

Laboratory tests: TSH > 40 mIU/L, aTPO > 1105 U/mL.

Ultrasound. The thyroid was hypoechogenic and inhomogeneous and presented fibrotic changes. There was a homogeneous and less hypoechogenic discrete lesion in the upper part of the left lobe.

Aspiration cytology from the discrete lesion resulted in Hashimoto's thyroiditis.

Comments.

1. It seems doubtful whether the discrete lesion is a true nodule or not.
   
2. The definition of the nodule depends on what to compare the echogenicity to. If the reference is the non-lesional part of the thyroid, then the lesion is hyperechoic. However, compared to a healthy thyroid, the nodule is hypoechoic.