Treatment of thyroid cysts with percutaneous ethanol injection

A woman had a noticeable mass on the left side of the neck which was confirmed to be a simple thyroid cyst larger than 2 cm in size. Interventional radiology performed ultrasound-guided fine-needle aspiration (FNA) and drained the cystic fluid. The FNA cytology was limited by scant cellularity but otherwise was benign.

Soon afterward, however, the thyroid cyst recurred — possibly larger than before. The cyst caused cosmetic concerns and also an uncomfortable sensation of fullness in her throat. Surgery was considered but the patient was hesitant. She did not want a scar and was concerned about risks associated with surgery. Therefore, she was sent to see me for further recommendations. I offered percutaneous ethanol injection (PEI) as an alternative to surgery.

Thyroid cyst before PEI.

The patient worked in a physician’s office. That physician did some reading on the internet. He questioned the safety of PEI and decided to call one of the surgeons in our community to ask his opinion. The surgeon said “it hurts and it doesn’t work,” but otherwise did not have any concerns.

After discussing the procedure in detail and answering her numerous questions, she agreed to proceed. Using ultrasound for guidance and paying special attention to make sure the 25-gauge needle tip did not penetrate the far wall of the cyst, I removed most of the fluid. The needle was left in place and I slowly injected sterile 95% ethanol into the cyst. I usually inject a volume of about 50% of the amount of cystic fluid that had been removed. The patient experienced mild transient burning only. She was surprised by how minimal the discomfort was. Later, she confessed to being apprehensive after having been told by her other physicians that PEI was very painful.

A few weeks later she returned. The cyst was no longer noticeable or palpable. A follow-up ultrasound revealed it was still present but much less prominent than before. It may shrink even further in the coming weeks and months. However, even if the cyst does not completely disappear, both she and I were pleased to have achieved our goal of eliminating symptoms and cosmetic concerns without having to resort to surgery.

Thyroid cyst after PEI.

Most thyroid cysts do not require intervention. However, for those causing cosmetic and/or anatomic concerns, PEI can be a safe and effective non-surgical treatment option. When done by an experienced thyroidologist, the risks of PEI are low. The most common adverse event is minor transient burning. Only a very few cases of non-permanent laryngeal nerve injury and dysphonia have been reported. This is much less than the frequency of complications when attempting PEI of a solid nodule (which is why I perform PEI only for thyroid cysts, never solid nodules).

Compared with simple aspiration, PEI of thyroid cysts results in an 85.6% vs. 7.3% reduction in cystic volume, as well as 74.8% vs. 24.4% resolution of compressive symptoms and 80% vs. 37.4% disappearance of cosmetic concerns. There is greater reduction of volume after PEI of simple thyroid cysts compared with cysts with solid portions (88.8% vs. 65.8%). Most thyroid cysts respond to a single PEI treatment; however, occasional patients may require additional treatments.

For more information:

Valcavi R. Endocr Pract. 2004;10:269-275.