Thyroid Nodules Referral Guidelines

Diagnosis/Definition

Approximately 1% of men and 5% of women have palpable thyroid nodules.

• Up to 67% of individuals have thyroid nodules that can be detected by ultrasound. Due to the increase in neck imaging with various modalities, many non-palpable nodules are being discovered.
• Thyroid nodules can be cystic, solid or mixed (cystic/solid).
• Thyroid cancer occurs in 5-15% of thyroid nodules depending on age, sex, radiation exposure history, family history and other factors.
• The risk of cancer in a purely cystic nodule is <2%.
• The risk of cancer in a thyroid nodule is the same whether it is a solitary nodule or one of several in a multi-nodular goiter.

Initial Diagnosis and Management

• History: Thyroid nodules can be found in patients of any age. The age of the patient and the sex are relevant factors in determining risk of malignancy. The history should evaluate for symptoms of hypo- or hyperthyroidism. Other important historical facts include voice changes, dysphagia, aspiration symptoms, cachexia, weight loss, prior history of radiation therapy.
• Physical Examination: The physical exam should focus on the thyroid gland and the surrounding lymph nodes. The overall size and consistency of the gland as well as the number and size of the thyroid nodules should be evaluated. A thorough examination of the neck for evidence of cervical lymphadenopathy should be performed.
• Ancillary Tests: If a thyroid nodule is suspected obtain a TSH and a thyroid ultrasound.
  Ongoing Management and Objectives
• Thyroid nodules require evaluation to determine the potential for malignancy.
• The nodules that are confirmed to be malignant or indeterminate lesions require surgical resection.
  Indications for Specialty Care Referral
• All thyroid nodules with features concerning for malignancy require a thorough evaluation by a specialty care clinic (Endocrinology Service/Otolaryngology-Head and Neck Surgery Service). These include: palpable nodules, nodules 1.0 cm or larger in size, nodules with ultrasound features concerning for malignancy even if less than 1cm in size*, and nodules enlarging on serial ultrasound studies.
• Small thyroid nodules (<1.0 cm), incidentally noted on imaging studies for other problems, with benign features on ultrasound, may initially be observed with a follow up ultrasound in 4-6 months. If these nodules enlarge then the patient should be referred for subspecialty evaluation.
• Fine needle aspiration of thyroid nodules is the test of choice. This can be performed as an outpatient during the initial evaluation with sensitivities approaching 96%.
  
  *ultrasound features of a thyroid nodule that are suspicious for cancer include the following: nodule hypoechogenicity, microcalcifications, increased intranodular vascularity, irregular infiltrative margins, absent halo, shape taller than width.