Keyword

1 Case Presentation

A 76-year-old female patient presented to our thyroid polyclinic for neck swelling. A thyroid function test demonstrated normal results. Thyroid ultrasound (USG) and thyroid scintigraphy were performed. A gross cystic thyroid nodule was seen in the thyroid USG (Fig. 12.1).

Fig. 12.1
figure 1

Thyroid USG of the patient before percutaneous ethanol injection. Maximum diameters of the cystic nodule measured 44.9 × 36.7 × 35.7 mm

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The volume of thyroid nodule was automatically calculated using the ellipsoid formula ([length × width × height] × π/6). The width was measured as the maximum transverse diameter, and the height was measured as the maximum anterior-posterior diameter perpendicular to the width. The length of the thyroid nodule was measured as the maximum longitudinal diameter on longitudinal US images. The maximum diameters of the cystic nodule were measured as 44.9 × 36.7 × 35.7 mm, and the nodule volume was measured as 30.85 ml. Thyroid scintigraphy with Tc-99m pertechnetate was performed to evaluate the real volume of the nodule and to exclude the solid part of the nodule (Fig. 12.2).

Fig. 12.2
figure 2

Thyroid scintigraphy with Tc-99m pertechnetate. There is gross hypoactive thyroid nodule can be seen in the right thyroid lobe

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This patient was wheelchaired and could not go to operation because of cardiac problems. She had respiratory problems because of the gross thyroid nodule. Percutaneous ethanol injection (PEI) therapy was recommended, and she accepted the therapy. After the evacuation of the cystic content of nodule, 95% ethanol was instilled under sonographic guidance with a 21-gauge needle. In our procedure, ethanol was not reevacuated. The amount of alcohol injected was about 50% of the amount of fluid aspirated. Gentle pressure was applied over the puncture site for 10–15 min, and the patient was watched for signs of any complication. Before ethanol injection intranodular local anesthesia was given to reduce pain. After the ethanol injection, the needle was washed with 1–2 ml of saline into the nodule. The saline rinse prevents ethanol leakage through the superficial tissues, which may cause intense pain to the patient. This procedure is so effective to reduce complications such as discomfort and pain. No major side effect was observed apart from a transient pain by the patient.

Thyroid USG was performed at every follow-up visit to assess the cyst volume. It was performed every week after ethanol injection for the first month. Four months after the therapy, the diameters of the nodule were measured as 24.7 × 25.6 × 24.2 mm, and nodule volume was measured as 8.01 ml (Fig. 12.3). Therapeutic success was defined as a noticeable reduction of volume and disappearance of clinical symptoms. Also, a complete esthetic satisfaction was reported by the patient.

Fig. 12.3
figure 3

Thyroid USG after the percutaneous ethanol injection. Four months after the therapy, diameters of the nodule measured 24.7 × 25.6 × 24.2 mm. The volume of the cystic nodule decreased from 30.85 to 8.01 ml

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2 Discussion

The objective of this case is to evaluate the efficacy and safety of PEI in the treatment of benign cystic thyroid nodules. Ethanol injection causes irreversible tissue damage through cellular dehydration, protein denaturation, and coagulative necrosis. PEI is used only for benign thyroid nodules and cystic or mixed cystic-solids with large fluid components. PEI method can be used in solitary thin-walled thyroid cysts larger than 10 mm, cystic big nodules with compression of neck organs in elderly and seriously ill patients to reduce the lesion volume. USG-guided PEI can be used for outpatients and is quite a low-cost, safe method of treatment.

PEI for the treatment of thyroid and parathyroid lesions was introduced into clinical practice in 1990 [1]. Ethanol injection causes irreversible tissue damage through cellular dehydration, protein denaturation, and coagulative necrosis. This technique was initially proposed as an alternative to surgery or radioiodine administration in thyroid nodules, but the use of PEI for this purpose has sensibly decreased. Ethanol has been successfully used in the treatment of cystic thyroid nodules for a long time.

Cystic thyroid lesions with a predominant fluid component are a frequent finding, representing up to 32% of all thyroid nodules [2]. Pure thyroid cysts are less frequent, corresponding to about 1% of thyroid nodules [3]. The majority of these nodules are asymptomatic. Sometimes they may cause compressive or cosmetic discomfort because of their size and location. Fine-needle aspiration (FNA) of the fluid content may reduce the lesion size; however, in 80% of the cases, thyroid cysts recur after aspiration [4]. Treatment of benign cystic thyroid nodules is usually undertaken for cosmetic reasons or local compressive symptoms [5]. Surgery is curative but has disadvantages, such as general anesthesia-related complications, scar formation, and hypothyroidism. PEI therapy is effective in reducing size of cystic thyroid nodules. Ethanol volume to be introduced into the nodule is determined individually, depending on nodule size and nodule cyst content. In our case, the amount of alcohol injected was about 50% of the amount of fluid aspirated. In our procedure, ethanol was not reevacuated. Some authors claim that complete evacuation of infused ethanol avoids the risk of ethanol leakage and any related complications. Available data comparing the two different technics, there are no differences in term of successful results [6].

Cystic nodules with volumes >20 ccs may need more number of alcohol injections and longer follow-ups. Tarantino et al. and Zingrillo et al. showed that nodules with mean volume >38 ml showed significant reduction in size after 2 years [7, 8]. According to some researchers, successful PEI in thyroid nodules is characterized by a reduction in nodule size of 2–3 times with replacement by connective tissue within 6 months [9].

Ethanol sclerotherapy is also associated with some complications. Mild transient pain and a burning sensation at the site of injection are the most commonly seen side effects. The most frequently reported complaint is pain [10]. In most cases, pain is due to leakage of ethanol into subcutaneous tissue during needle extraction. This can be prevented by rinsing the needle tip with a small amount of saline before extracting the needle. Uncommon complications include hematoma, dyspnea, and vocal cord paralysis [10]. The most severe complication of PEI is unilateral cord paralysis due to the toxic action of absolute ethanol on the recurrent laryngeal nerve. Our patient did not show any complications or side effects.

Use of PEI is limited in multichambered cysts, multiple small cysts, or isoechoic nodules larger than 30 mm [11]. Particular attention should be paid when PEI is performed in the nodules located in the dorsal compartments of the thyroid lobes.

What Can We Learn from This Case?

  • Ethanol sclerotherapy is an effective and safe nonsurgical treatment option for benign cystic thyroid nodules.

  • Cystic nodules with volumes >20 ccs may need more number of alcohol injections and longer follow-up before results become evident.