Goiter Treatment & Management

Small benign euthyroid goiters do not require treatment. The effectiveness of medical treatment using thyroid hormone for benign goiters is controversial. Large and complicated goiters may require medical and surgical treatment. Malignant goiters require medical and surgical treatment.

• The size of a benign euthyroid goiter may be reduced with levothyroxine suppressive therapy. The patient is monitored to keep serum TSH in a low but detectable range to avoid hyperthyroidism, cardiac arrhythmias, and osteoporosis. The patient has to be compliant with monitoring. Some authorities suggest suppressive treatment for a definite time period instead of indefinite therapy. Patients with Hashimoto thyroiditis respond better.

• Treatment of hypothyroidism or hyperthyroidism often reduces the size of a goiter.

• Thyroid hormone replacement is often required following surgical and radiation treatment of a goiter. Use of radioactive iodine for the therapy of nontoxic goiter has been disappointing and is controversial.

• Medical therapy of autonomous nodules with thyroid hormone is not indicated.

• Ethanol infusion into benign thyroid nodules has not been approved in the United States, but it is used elsewhere.

Goiters with primary thyroid malignancy require levothyroxine replacement after surgery and radioactive iodine ablation. Metastatic lesions to the thyroid gland require treatment of the primary malignancy. Granulomatous and infectious etiologies for goiter require specific treatment depending on the underlying cause.

Surgery is reserved for the following situations:

• Large goiters with compression

• Malignancy

• When other forms of therapy are not practical or are ineffective

Preoperatively, establish euthyroid state prior to surgical treatment. Evaluation must include the stability of the airway. This must be secured immediately if ventilatory status appears tenuous. Emergency surgical treatment of a goiter in a patient with hypothyroidism requires intravenous levothyroxine and glucocorticoids at stress doses.

Emergency surgical treatment of a goiter in a thyrotoxic patient requires antithyroid medications, beta blockers, and glucocorticoids at stress doses. Suppressive doses of iodine are helpful.

Intraoperative and postoperative management includes hemodynamic monitoring, which is important in patients with preoperative hyperthyroidism or hypothyroidism.

Postoperative management also includes monitoring of serum calcium.

A literature review by Li et al indicated that total thyroidectomy is a safe procedure for the treatment of bilateral multinodular nontoxic goiter, demonstrating a lower recurrence rate than bilateral subtotal thyroidectomy. However, total thyroidectomy was also found to carry a significantly higher risk of postoperative transient hypoparathyroidism than did the other procedure. ^[16]

A study by Finnerty et al indicated that in patients with multinodular goiter who undergo total thyroidectomy, a higher score on the 5-factor modified frailty index is more predictive of thyroidectomy-specific complications, including hematoma and recurrent laryngeal nerve palsy, than is older age. ^[17]

A retrospective study by Frank et al indicated that in patients with hyperthyroidism who undergo total thyroidectomy, the complication rate, including with regard to transient hypocalcemia, temporary dysphonia, and postoperative hematoma, does not differ significantly from that for the procedure in patients with benign euthyroid or malignant thyroid disease. The investigators also found that among the patients with hyperthyroidism, the complication rates were similar between those with Graves disease and patients with toxic multinodular goiter. ^[18]

A study by Khan et al indicated that in patients with retrosternal goiter, a transcervical surgical approach is preferable to a transthoracic procedure. The study, which employed the National Surgical Quality Improvement Program (NSQIP) database, found that various postoperative morbidities, including those involving transfusions and unplanned intubations, were higher with the transthoracic approach. The data suggested that overall mortality might be increased as well with this procedure. ^[19]

A study by Bove et al indicated that in patients with retrosternal goiter, recurrence and extension of the goiter beyond the carina are preoperative risk factors for postoperative complications following total thyroidectomy. The study also found evidence that compared with total thyroidectomy for cervical goiter, the risk for transient hypocalcemia and transient recurrent laryngeal nerve palsy is greater following the same procedure for retrosternal goiter. ^[20]

An endocrinologist should assess a patient at least once, and assessment should be even more frequent if the goiter is complicated by thyroid dysfunction or malignancy or if the patient is being considered for surgical management.

Nutrition plays a role in the development of endemic goiters. Dietary factors include iodine deficiency, goitrogens, protein malnutrition, and energy malnutrition. Often these factors occur concurrently.

• Iodine: If it is practical, treat endemic goiters in iodine-deficient regions with iodine supplementation in the diet and avoidance of goitrogens. Treatment with iodine supplementation or levothyroxine may reduce goiter size. ^[5]

• Goitrogens: Cyanoglucosides are naturally occurring goitrogens that are digested to release cyanide, which is converted to thiocyanate. Thiocyanate inhibits iodide transport in the thyroid and, at higher levels, inhibits organification. Foods that contain cyanoglucosides include cassava, lima beans, maize, bamboo shoots, and sweet potatoes. Thioglucosides are natural goitrogens found in the Cruciferae family of vegetables and weeds eaten by animals. When digested, they release thiocyanate and isothiocyanate, which have thionamidelike properties and are passed to humans via milk ingestion.

Potential complications include the following:

• Large goiters may cause compression of the trachea, with tracheomalacia and asphyxiation.

• Hyperthyroidism occurs in some patients exposed to iodine (ie, Jodbasedow phenomenon).

• A patient with autoimmune goiters may develop lymphoma. Multinodular goiters may undergo malignant transformation.

• Nodular goiters may cause pain, intranodular necrosis, or hemorrhage.

• Thyroid abscess may be associated with pain, fever, bacteremia, or sepsis.

Goiter prevention is based on etiology.

Correct iodine deficiency ^[5]  and avoid dietary or iatrogenic goitrogens if practical. In the United States, it is difficult to find iodine deficiency, given the supplementation of table salt with iodine, iodine in cattle feed, and the use of iodine as a dough conditioner. Judicious use of levothyroxine is helpful in patients with a previous diagnosis of nodular hyperplasia who have had a lobectomy to prevent occurrences in the contralateral lobe.

Goiters due to autoimmune thyroiditis may be controlled with careful use of levothyroxine and, when indicated, anti-inflammatory medication.

Congenital goiters due to inborn errors of metabolism may be reduced or prevented by careful use of levothyroxine during the postpartum period. Newborns are screened for congenital hypothyroidism.

Patients are monitored for hypothyroidism by history, examination, and TSH measurements. Initially, monitoring occurs every 6-8 weeks.