Guideline Grading System

Diagnosis

1. Screening people with familial follicular cell-derived differentiated thyroid cancer may lead to an earlier diagnosis of thyroid cancer, but the panel cannot recommend for or against ultrasound screening since there is no evidence that this would lead to reduced morbidity or mortality. (NR-I)
2. A) Serum TSH should be measured during the initial evaluation of a patient with a thyroid nodule. (SR-M)
   B) If the serum TSH is subnormal, a radionuclide (preferably 123I) thyroid scan should be performed. (SR-M)
   C) If the serum TSH is normal or elevated, a radionuclide scan should NOT be performed as the initial imaging evaluation (SR-M)
3. Routine measurement of serum Tg for initial evaluation of thyroid nodules is NOT recommended. (SR-M)
4. The panel cannot recommend either for or against routine measurement of serum calcitonin in patients with thyroid nodules. (NR-I)
5. A) Focal ¹⁸FDG-PET uptake within a sonographically confirmed thyroid nodule conveys an increased risk of thyroid cancer, and fine needle aspiration is recommended for those nodules >1 cm. (SR-M)
   B) Diffuse ¹⁸FDG-PET uptake, in conjunction with sonographic and clinical evidence of chronic lymphocytic thyroiditis, does not require further imaging or fine needle aspiration. (SR-M)
6. Thyroid sonography with survey of the cervical lymph nodes should be performed in all patients with known or suspected thyroid nodules. (SR-H)
7. FNA is the procedure of choice in the evaluation of thyroid nodules, when clinically indicated (SR-H)
8. Thyroid nodule diagnostic FNA is recommended for
   (Figure 2, Table 1):
   A) Nodules >1 cm in greatest dimension with high suspicion sonographic pattern (SR-M )
   B) Nodules >1 cm in greatest dimension with intermediate suspicion sonographic (SR-L)
   C ) Nodules >1.5 cm in greatest dimension with low suspicion sonographic pattern (WR-L )
   Thyroid nodule diagnostic FNA may be considered for
   (Figure 2, Table 1):
   D) Nodules >2 cm in greatest dimension with very low suspicion sonographic pattern (e.g., – spongiform). Observation without FNA is also a reasonable option (WR-M)
   Thyroid nodule diagnostic FNA is not required for (Figure 2, Table 1):
   E) Nodules that do not meet the above criteria. (SR-M )
   F) Nodules that are purely cystic (SR-M)
9. Thyroid nodule FNA cytology should be reported using diagnostic groups outlined in the Bethesda System for Reporting Thyroid Cytopathology (http://ajcp.ascpjournals.org/cgi/pmidlookup?view=long&pmid=20660341) (SR-M)
10. A) For a nodule with an initial nondiagnostic cytology result, FNA should be repeated with US guidance and, if available, on-site cytologic evaluation (SR-M)
    B) Repeatedly nondiagnostic nodules without a high suspicion sonographic pattern require close observation or surgical excision for histopathologic diagnosis ( WR-L)
    C) Surgery should be considered for histopathologic diagnosis if the cytologically nondiagnostic nodule has a high suspicion sonographic pattern, growth of the nodule (greater than 20% in two dimensions) is detected during ultrasound surveillance, or clinical risk factors for malignancy are present (WR-L)
11. If the nodule is benign on cytology, further immediate diagnostic studies or treatment are not required (SR-H)
12. If a cytology result is diagnostic for primary thyroid malignancy, surgery is generally recommended. (SR-M)
13. If molecular testing is being considered, patients should be counseled regarding the potential benefits and limitations of testing, and about the possible uncertainties in the therapeutic and long-term clinical implications of results. (SR-L)
14. If intended for clinical use, molecular testing should be performed in CLIA/CAP (Clinical Laboratory Improvement Amendments/College of American Pathologists) certified molecular laboratories, or international equivalent, as reported quality assurance practices may be superior compared to other settings. (SR-L)
15. A) For nodules with AUS/FLUS cytology, after consideration of worrisome clinical and sonographic features, investigations such as repeat FNA or molecular testing may be used to supplement malignancy risk assessment in lieu of proceeding directly with a strategy of either surveillance or diagnostic surgery. Informed patient preference and feasibility should be considered in clinical decision-making. (WR-M)
    B) If repeat FNA cytology and/or molecular testing are not performed or inconclusive, either surveillance or diagnostic surgical excision may be performed for an AUS/FLUS thyroid nodule, depending on clinical risk factors, sonographic pattern, and patient preference. (SR-L)
16. A) Diagnostic surgical excision is the long-established standard of care for the management of follicular neoplasm/suspicious for follicular neoplasm (FN/SFN) cytology nodules. However, after consideration of clinical and sonographic features, molecular testing may be used to supplement malignancy risk assessment data, in lieu of proceeding directly with surgery. Informed patient preference and feasibility should be considered in clinical decision-making. (WR-M)
    B) If molecular testing is either not performed or inconclusive, surgical excision may be considered for removal and definitive diagnosis of an FN/SFN thyroid nodule. (SR-L)
17. A) If the cytology is reported as suspicious for papillary carcinoma (SUSP), surgical management should be similar to that of malignant cytology, depending on clinical risk factors, sonographic features, patient preference, and possibly results of mutational testing (if performed). (SR-L)
    B) After consideration of clinical and sonographic features, mutational testing for BRAF or the 7-gene mutation marker panel (BRAF, RAS, RET/PTC, PAX8/PPAR γ) may be considered in nodules with SUSP cytology if such data would be expected to alter surgical decision-making. ( WR-M)
18. ¹⁸FDG-PET imaging is not routinely recommended for the evaluation of thyroid nodules with indeterminate cytology. ( WR-M)

Figure 1. Evaluation and Management of Patients With Thyroid Nodules Based on US Pattern and FNA Cytology

Figure 2. ATA Nodule Sonographic Patterns and Risk of Malignancy

Figure 3. Lymph Node Compartments Separated into Levels and Sublevels