para>Patients with high risk of malignancy include those with:
- History of neck and head irradiation
- Family history of thyroid cancer
- Male sex
- Young or elderly
- Symptoms of dysphagia, dysphonia, or dyspnea
- Clinical findings of:
- Cervical adenopathy
- Firm, hard, or fixed nodules
- Rapidly growing nodule
DIAGNOSTIC PROCEDURES/OTHER
Fine needle aspiration biopsy
- Suspicious findings by history, physical exam, or ultrasound
- Ultrasound-guided biopsy is preferred because of improved diagnostic accuracy and less nondiagnostic samples (2)[C].
Test Interpretation
- TSH elevated = hypothyroidism
- Verify with free T4-should be low.
- Most are Hashimoto thyroiditis. TPO antibodies are elevated. Many become nodular over time
- TSH suppressed = hyperthyroidism
- Verify with elevated free T4. If TSH suppressed, but T4 is low or normal, obtain free T3 (T3 RIA) for unusual cases of T3 thyrotoxicosis.
- Most are Graves disease. Should have homogeneous increased uptake on scintigraphy. TRAb are generally present.
- If scintigraphy demonstrates nodular gland with increased uptake in single nodule, this represents toxic adenoma (Plummer syndrome).
- If scintigraphy demonstrates increased uptake in multiple nodules, this is toxic multinodular goiter.
- Rarely, there will be decreased uptake on scintigraphy. This is likely the temporary, toxic phase of thyroiditis. Most cases will become euthyroid over time, with many later developing hypothyroidism.
- TSH normal = euthyroidism
- Ultrasound shows diffuse enlargement without nodules. Monitor for growth and development of symptoms. Consider monitoring TSH on regular basis.
- Ultrasound demonstrates nodular gland suspicious for malignancy because of patient or ultrasound characteristics. Biopsy any suspicious nodule.
TREATMENT
MEDICATION
First Line
- Hypothyroid-L-thyroxine
- Hyperthyroid-iodine-131, although in Europe, antithyroid drugs are frequently considered first line.
- Euthyroid-no consensus. Observation or treatment based on goiter size, compressive symptoms, and patient risk factors and preferences. May shrink goiter with iodine-131 or L-thyroxine, but complications and conflicting evidence of efficacy may be reasons to use observation or surgery instead.
Second Line
Hyperthyroidism-propylthiouracil (PTU) or methimazole
- Treatment for 12 to 18 months using a low-dose titration method is effective with fewer adverse effects than high-dose treatment (4)[A].
- Risks include hepatotoxicity (black box warning with PTU), agranulocytosis and other hematologic abnormalities, rash, nausea and vomiting, vasculitis (rare).
- Methimazole is generally preferred due to lower risk profile.
Pregnancy Considerations
ISSUES FOR REFERRAL
- Iodine-131 (I-131) dosing is usually done by nuclear medicine or endocrinologist.
- General or endocrine surgeon for partial or total thyroidectomy
- Endocrinologist when diagnosis is in doubt or response to treatment is suboptimal
- Endocrinologist, thyroid surgeon, or interventional radiologist for FNAB
ADDITIONAL THERAPIES
Symptomatic improvement in hyperthyroid symptoms may be seen with β-blockers.
SURGERY/OTHER PROCEDURES
Indicated in select cases
- Cosmetic-large goiters in patients desiring surgery for cosmesis
- Obstruction-patients with symptoms of compression, including dysphagia, difficulty breathing, or speech difficulties
- Diagnostic-patients with suspicious nodules and indeterminate FNAB
- Curative-patients with suspicious FNAB or other findings suggestive of cancer (rapid growth, abnormal texture, associated adenopathy)
- May also be done in patients who fail other treatments or who prefer surgical treatment over other, less-invasive treatments for Grave disease, single toxic adenoma, or toxic multinodular goiter. When surgery is chosen, total thyroidectomy has less risk of recurrence of hyperthyroidism than subtotal thyroidectomy with comparable surgical risks (6,7)[A].
ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
Patient Monitoring
- Ultrasound annually for nodular goiter
- TSH annually for euthyroid goiters to detect development of hypothyroidism in thyroiditis or hyperthyroidism in nodular goiters
- Following treatment, monitoring as appropriate depending on the underlying diagnosis
DIET
Generally not a factor in the United States, but adequate iodine intake likely prevents many goiters.
PROGNOSIS
Varies according to diagnosis
- Therapy is very effective at treating physiologic parameters.
- Physical size of goiter may not respond significantly to treatment other than surgery.
- Cancer is uncommon in adults with nodular goiters. Only 5-10% of nodules are cancerous. Most of these are papillary and have a survival rate over 90%.
Pediatric Considerations
Cancer risk is significantly higher in children younger than 14 years of age.
COMPLICATIONS
- Thyroid storm-rare complication of severe hyperthyroidism. May result in psychological and/or cardiac symptoms
- Myxedema coma-rare complication of severe hypothyroidism. May cause cognitive changes, coma, or death
- Compressive symptoms may include dysphagia, breathing difficulties, or vocal cord paralysis
- Complications of treatment
- Surgical complications include infection, bleeding, vocal cord paralysis from laryngeal nerve damage, hypothyroidism, and hypoparathyroidism.
- I-131 rarely causes transient thyrotoxicosis and frequently leads to hypothyroidism over time.
- Complications of antithyroid medications include rash, neutropenia, and hypothyroidism (usually temporary).
REFERENCES
11 Constantinides V, Palazzo F. Goitre and thyroid cancer. Medicine. 2013;41:546-550.22 Gharib H, Papini E, Paschke R, et al. American Association of Clinical Endocrinologists, Associazione Medici Endocrinologi, and European Thyroid Association medical guidelines for clinical practice for the diagnosis and management of thyroid nodules: executive summary of recommendations. Endocr Pract. 2010;16(3):468-475.33 Tozzoli R, Bagnasco M, Giavarina D, et al. TSH receptor autoantibody immunoassay in patients with Graves' disease: improvement of diagnostic accuracy over different generations of methods. Systematic review and meta-analysis. Autoimmun Rev. 2012;12(2):107-113.44 Abraham P, Avenell A, McGeoch SC, et al. Antithyroid drug regimen for treating Graves' hyperthyroidism (review). Cochrane Database Syst Rev. 2010;(1):CD003420.55 Stagnaro-Green A, Abalovich M, Alexander E, et al. Guidelines of the American Thyroid Association for the diagnosis and management of thyroid disease during pregnancy and postpartum. Thyroid. 2011;21(10):1081-1125.66 Feroci F, Rettori M, Borrelli A, et al. A systematic review and meta-analysis of total thyroidectomy versus bilateral subtotal thyroidectomy for Graves' disease. Surgery. 2014;155(3):529-540.77 Guo Z, Yu P, Liu Z, et al. Total thyroidectomy vs bilateral subtotal thyroidectomy in patients with Graves' disease: a meta-analysis of randomized clinical trials. Clin Endocrinol (Oxf). 2013;79(5):739-746.
CODES
ICD10
- E04.9 Nontoxic goiter, unspecified
- E04.2 Nontoxic multinodular goiter
- E05.00 Thyrotoxicosis w diffuse goiter w/o thyrotoxic crisis
- E03.0 Congenital hypothyroidism with diffuse goiter
- E04.1 Nontoxic single thyroid nodule
- E04.0 Nontoxic diffuse goiter
- E04.8 Other specified nontoxic goiter
ICD9
- 240.9 Goiter, unspecified
- 241.1 Nontoxic multinodular goiter
- 242.00 Toxic diffuse goiter without mention of thyrotoxic crisis or storm
- 246.1 Dyshormonogenic goiter
- 241.9 Unspecified nontoxic nodular goiter
- 240.0 Goiter, specified as simple
SNOMED
- Goiter (disorder)
- Non-toxic multinodular goiter
- Toxic diffuse goiter with no crisis (disorder)
- Dyshormonogenic goiter (disorder)
- multinodular goiter (disorder)
- toxic uninodular goiter (disorder)
- Graves disease (disorder)
- toxic nodular goiter (disorder)
- Nodular goiter (disorder)
- Toxic diffuse goiter (disorder)
- Non-toxic uninodular goiter
- Uninodular goiter (disorder)
CLINICAL PEARLS
- TSH is best initial screening test for both hypothyroidism and hyperthyroidism.
- Any nodule with suspicious features by history, exam, or ultrasound should be biopsied.
- Treatment of goiter should be based on the risk of malignancy, the function of the gland, and compressive symptoms. Patient preference should also be taken into account, particularly with hyperthyroid goiters.
- Hyperthyroidism can be successfully treated with I-131, antithyroid drugs, or surgery. The choice of treatment is dependent on the presence of compressive symptoms, potential risks of treatment, and patient preference.