Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 26-10: Thyroid Nodules & Multinodular Goiter + Key Features Download Section PDF Listen +++ +++ Essentials of Diagnosis ++ Single or multiple thyroid nodules are commonly palpated by the patient or clinician or discovered incidentally on imaging studies Thyroid function tests recommended Fine-needle aspiration (FNA) cytology for thyroid nodules ≥ 1 cm or for smaller nodules in patients with a history of prior head-neck or chest-shoulder radiation Ultrasound guidance improves FNA diagnosis for palpable and nonpalpable nodules Clinical follow-up required +++ General Considerations ++ About 90% of palpable thyroid nodules are benign adenomas, colloid nodules, or cysts, but some are primary thyroid malignancies or (less frequently) metastatic malignancy Most patients with a thyroid nodule are euthyroid, but there is a high incidence of hypothyroidism or hyperthyroidism Patients with multiple thyroid nodules have the same overall risk of thyroid cancer as patients with solitary nodules The risk of a thyroid nodule being malignant is higher in males and among patients with History of head-neck radiation, total body radiation for bone marrow transplantation, exposure to radioactive fallout as a child or teen Family history of thyroid cancer or a thyroid cancer syndrome (eg, Cowden syndrome, multiple endocrine neoplasia type 2, familial polyposis, Carney syndrome) Personal history of another malignancy Hoarseness or vocal fold paralysis, adherence to the trachea or strap muscles, cervical lymphadenopathy Thyroid nodules that are solitary or large (≥ 4.5 cm max diameter) The presence of autoimmune (Hashimoto) thyroiditis does not reduce the risk of malignancy; a nodule of 1 cm or larger in a gland with thyroiditis carries an 8% chance of malignancy +++ Demographics ++ They are much more common in women than men and become more prevalent with age Palpable nodules occur in 4–7% of all adults in the United States Thyroid nodules are more common in iodine-deficient regions + Clinical Findings Download Section PDF Listen +++ +++ Symptoms and Signs ++ Small thyroid nodules usually asymptomatic; may be detected by having the patient swallow during palpation of the thyroid Nodules can grow large enough to cause discomfort, hoarseness, or dysphagia Nodules that cause ipsilateral recurrent laryngeal nerve palsy are more likely to be malignant Retrosternal large multinodular goiters can cause dyspnea due to tracheal compression Large substernal goiters may cause superior vena cava syndrome, manifested by facial erythema and jugular vein distention that progress to cyanosis and facial edema when both arms are kept raised over the head (Pemberton sign) Depending on their cause, goiters and thyroid nodules may be associated with Hypothyroidism (autoimmune thyroiditis, endemic goiter) Hyperthyroidism (Graves disease, toxic nodular goiter, subacute thyroiditis, and thyroid cancer with metastases) +++ Differential Diagnosis ++ Iodine-deficient goiter Pregnancy (in areas of iodine deficiency) Graves disease Hashimoto thyroiditis Subacute (de Quervain) thyroiditis Drugs causing hypothyroidism Amiodarone Interferon-alpha Iodide Lithium Methimazole Propylthiouracil Sulfonamides Infiltrating disease, eg, malignancy, sarcoidosis Suppurative thyroiditis Riedel thyroiditis Nonthyroid neck mass, eg, lymphadenopathy, lymphoma, branchial cleft cyst + Diagnosis Download Section PDF Listen +++ +++ Laboratory Tests ++ A serum TSH and FT4 determine if the thyroid is hyperfunctioning Radionuclide thyroid scan (123I or 99mTc pertechnetate) Obtain in patients with a subnormal serum TSH Determines whether the nodule is hyperfunctioning Hashimoto thyroiditis Antithyroperoxidase and antithyroglobulin antibody titers usually very high +++ Imaging Studies ++ Neck ultrasonography should be performed Preferred over CT and MRI Malignant nodules are more likely to grow more than 2 mm/yr CT scanning can determine the degree of tracheal compression and the degree of extension into the mediastinum +++ Diagnostic Procedures ++ Fine-needle aspiration (FNA) biopsy of suspicious nodules (thyroiditis frequently coexists with malignancy) FNA biopsy success is increased by ultrasound guidance + Treatment Download Section PDF Listen +++ +++ Medications ++ Levothyroxine, starting doses of 50 mcg daily, if serum TSH is elevated Consider "suppression" of nodules > 2 cm with levothyroxine, 50 mcg orally daily, even if serum TSH is normal Avoid if baseline TSH is low, suggesting autonomous secretion of thyroid hormone secretion from the nodule ("toxic adenoma"), because levothyroxine will be ineffective and may cause frank thyrotoxicosis Long-term suppression of TSH tends to keep nodules from enlarging and new nodules from developing, but few existing nodules actually shrink Works best for younger patients May increase risk for angina and arrhythmia in patients with cardiovascular disease Causes small loss of bone density in many postmenopausal women not taking estrogen or bisphosphonate +++ Surgery ++ Surgical resection indicated for solitary nodule in a patient with history of head–neck radiation due to risk of malignancy Surgical resection of toxic adenoma cures hyperthyroidism Surgical excision of multinodular goiter is indicated if causing compressive symptoms +++ Procedures ++ FNA of cystic nodule with fluid sent for cytology; multiple aspirations may be required because cysts tend to recur Ultrasound-guided radiofrequency ablation Therapeutic option for cytology-proven benign thyroid nodules that are large (3 cm or larger) and predominantly solid Shrinks such nodules by about 67% after 6 months Side effects include mild neck discomfort, swelling, bruising, and dysphagia that generally resolves within 5 days + Outcome Download Section PDF Listen +++ +++ Follow-Up ++ Thyroid nodules ≥ 1 cm warrant follow-up and further testing for function and malignancy A nodule < 1 cm requires follow-up if it has high-risk characteristics on ultrasound or if the patient is at high-risk for thyroid cancer due to prior head-neck radiation therapy during childhood All thyroid nodules, including those that are benign, need to be monitored by regular periodic palpation and ultrasound about every 6 months initially After several years of stability, yearly examinations are sufficient Thyroid nodules should be rebiopsied if growth occurs +++ Prognosis ++ Benign nodules usually persist or grow slowly and may involute About 90% of thyroid nodules will increase their volume by 15% or more over 5 years; about 11% of nodules increase their volume by > 50% on follow-up Growth is more common with multinodular goiter, larger nodules, and in men Multinodular goiters tend to persist or grow slowly + References Download Section PDF Listen +++ + +Angell TE et al. Differential growth rates of benign vs. malignant thyroid nodules. J Clin Endocrinol Metab. 2017 Dec 1;102(12):4642–7. [PubMed: 29040691] + +Cohen RN et al. Management of adult patients with thyroid nodules and differentiated thyroid cancer. JAMA. 2017 Jan 24;317(4):434–5. [PubMed: 28118436] + +Durante C et al. The diagnosis and management of thyroid nodules: a review. JAMA. 2018 Mar 6;319(9):914–24. [PubMed: 29509871] + +Jawad S et al. Ultrasound-guided radiofrequency ablation (RFA) of benign symptomatic thyroid nodules—initial UK experience. Br J Radiol. 2019 Jun;92(1098):20190026. [PubMed: 31084496] + +Maxwell C et al. Clinical diagnostic evaluation of thyroid nodules. Endocrinol Metab Clin North Am. 2019 Mar;48(1):61–84. [PubMed: 30717911] + +Mayson SE et al. Molecular diagnostic evaluation of thyroid nodules. Endocrinol Metab Clin North Am. 2019 Mar;48(1):85–97. [PubMed: 30717912]