Thyroid cysts treated with ethanol ablation can mimic malignancy during sonographic follow-up

Area of Science:

• Endocrinology
• Radiology
• Oncology

Background:

• Percutaneous ethanol ablation (EA) is a treatment for benign thyroid cysts and cystic nodules.
• Post-treatment ultrasound (US) findings can be challenging to interpret.
• Long-term US characteristics after EA require thorough investigation.

Purpose of the Study:

• To evaluate long-term ultrasound findings following US-guided percutaneous ethanol ablation (EA).
• To assess the US appearance of benign thyroid cysts and predominantly cystic nodules post-EA.
• To identify US features that may be misinterpreted as malignancy after EA.

Main Methods:

• Retrospective analysis of US images from 40 patients (14 cysts, 26 nodules) post-EA.
• Long-term US follow-up ranging from 12 to 36 months (mean 18.2 months).
• Evaluation of nodule volume reduction and detailed US characteristics.

Main Results:

• Post-EA nodules exhibited features typically associated with malignancy, including marked hypoechogenicity (n=28) and spiculated margins (n=7).
• A significant proportion of nodules showed findings like microcalcifications (n=6) and taller-than-wide shape (n=2).
• US diagnoses ranged from benign to malignant, with 10 nodules classified as malignant and 20 as possibly malignant.

Conclusions:

• Long-term US follow-up after successful EA reveals a high incidence of findings mimicking malignancy.
• Awareness of these post-EA US changes is essential for clinicians.
• This knowledge can help prevent unnecessary fine-needle aspiration (FNA) procedures on treated nodules.