Sonographic changes in the thyroid gland after sclerotherapy with doxycycline can be mistaken for thyroid cancer.

For the work-up of a solitary suspicious thyroid lesion, the medical history of the patient should always be considered. In case of prior ipsilateral sclerotherapy, a reactive inflammatory response may mimic thyroid malignancy. A fine needle aspiration should be performed to exclude thyroid cancer. Treatment is not necessary; the process appears to be self-limiting as evidenced in the follow-up of this case.