First examination (first row of images):

Clinical presentation: a 52-year-old woman was referred for ethanol sclerotherapy. Her cystic nodule was three times drawn off but recurred within weeks and caused compression signs. Cytology resulted in non diagnostic, cystic degeneration.

Palpation: an elastic nodule in the isthmus.

Functional state: euthyroidism with TSH 1.76 mIU/L.

Ultrasonography. The thyroid was echonormal. There were several small cystic areas in the right lobe, while a large cyst was in the isthmus. The lesion contained a small, moderately hypoechogenic solid part which separated a small cystic area from the larger one. The solid portion contained smaller non-specific and a bit larger and more bright hyperechogenic granules.

We told the patient that the possibility of a papillary carcinoma cannot be excluded on ultrasound presentation even if the cytology would be benign. Surgery was advised.

An isthmusectomy was performed. Histopathology disclosed benign hyperplastic nodule.

Second examination 9 months after surgery (second row of images):

Clinical presentation: the patient had no complaints.

Palpation: no abnormality.

Ultrasonography: the right and the left lobe remained unchanged except for the appearance of a moderately hypoechogenic lesion in the lower, isthmic part of the right lobe. This lesion contained various hyperechogenic granules and was avascular on Doppler mode. The ultrasound presentation stood for a granulation around surgical thread.

Comments.

1. We perform sclerotherapy even if the cytology is non-diagnostic if the ultrasound presentation is calming. Vice versa we did not perform sclerotherapy of a cystic nodule in the event of benign cytology if the ultrasound presentation is suspicious.

2. The lesion which has appeared on post operative ultrasound might be a regenerative tissue or a granulation around surgical thread. The latter is more likely because the former usually disappears within 4 month after the operation.