Thyroid Nodules & Multinodular Goiter

Key Features

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

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

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