Thyroid Nodule, AACE/AME/ETA 2010

Summary - Symptoms or Signs That Warrant Further Investigation:
• Prior head and neck irradiation
• Family history of MTC or MEN2
• Age <20 years or >70 years
• Male sex
• Growing nodule or nodule >10 mm
• Firm or hard consistency of nodule; ill-defined nodule margins on palpation
• Cervical adenopathy
• Fixed nodule on examination
• Dysphonia, dysphagia, and cough

Ultrasound is the first step in diagnosis: (Cancer is not less common in nodules <10 mm)
1) Microcalcifications: small intra-nodular punctate hyper-echoic spots with scanty posterior acoustic
shadowing (Specificity for cancer: 85-95%) (Sensitivity: 30-60%)
2) Irregular or micro-lobulated margins (Spec: 83.0% to 85.0%) (Sens: 55-75%)
3) Hypervascularity & chaotic arrangement of intra-nodular vascular images (Spec: 81%) (Sens: 74%)
(i.e. arteriovenous shunts and tortuosity of vessel course)
4) Degenerative changes and multiple fluid areas
5) Extracapsular growth: Extension of irregular hypo-echoic lesions beyond the thyroid capsule
(Invasion of pre-thyroid muscles, posterior extra-capsular growth, or infiltration of the recurrent
laryngeal nerve demand immediate cytologic assessment)
6) Complex or Cystic Lesions: Most complex thyroid nodules with a dominant fluid component are
benign. However, US-FNA should be done because papillary carcinomas can rarely be cystic.
7) Suspicious Cervical Adenopathy: Enlarged rounded lymph nodes with no hilum, but with cystic
changes, micro-calcifications, or chaotic hypervascularity are always biopsied.
Hypo-echoic appearance (a decreased echogenicity in comparison with the surrounding parenchyma,
similar to that of the cervical strap muscles) + one of the first 3 US findings above indicates a subset of
non-palpable thyroid nodules that are high risk for cancer

Additional suspicious criteria:
1) Rounded appearance
2) “More tall (anteroposterior) than wide (transverse)” shape of the nodule
3) “Marked hypo-echogenicity” of a solid lesion (hypo-echoic compared to the cervical muscles)
The presence of 2 suspicious criteria reliably identifies most neoplastic lesions (~90% of cases)
It is generally possible to restrict the number of US-FNA procedures to about a third of the
impalpable thyroid nodules.


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, 2010