Assessment of thyroid lesions (general)
Updates to Article Attributes
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was changed:
Assessment of thyroid lesions is commonly encountered in radiological practice.
Thyroid mass breakdown
- hyperplastic/colloid nodule/nodular hyperplasia: 85%
- adenoma
- follicular: 5%
- others: rare
-
carcinoma
- papillary: 60-80% of carcinomas
- follicular: 10-20%
- medullary: 5%
- anaplastic: 1-2%
- thyroid lymphoma: 1%
- metastases to the thyroid: 1%
- others
Risk factors of a nodule being malignant
- young
- male
- solitary
- cold on thyroid scan
- past history of radiotherapy
The first three risk factors are really a reflection that elderly women with multiple benign thyroid nodules are very common.
Radiographic features
Ultrasound
- taller-than-wide in axial/transverse dimension, microcalcifications, local invasiveness, microlobulated contour, and hypoechogenicity are suspicious features
- size criteria are controversial and continously evolving
- cervical lymphadenopathy is a
suspiciousfeature - for detailed assessment, see: assessment of thyroid lesions (ultrasound)
Nuclear medicine
A single 'cold' nodule has a 10% chance of being malignant. A single 'hot' nodule has <1% chance of being malignant.
Treatment and prognosis
Indications for FNA
The criteria developed by the American Thyroid Association (2015) 11 are often used in clinical practice. See: ATA guidelines for assessment of thyroid nodules.
Indications for FNA according to Society of Radiologists in Ultrasound (2008) 4
- nodule ≥1.0 cm at the largest diameter if microcalcifications are present
- nodule ≥1.5 cm if the nodule is solid or if there are coarse calcifications within the nodule
Additional recommendations for FNA by the American Association of Clinical Endocrinologists 4:
- FNA recommended for nodules <`10 mm whenever clinical information or ultrasound features raises suspicion about the presence of a malignancy
Size criteria for indication for FNA according American Thyroid Association(2015) 11:
-
FNA is recommended for:nodules ≥1 cm with highly or intermediately suspicious sonographic featuresnodules ≥1.5 cm with low suspicious sonographic features
-
FNA may be considered for:-
nodules ≥2 cm with very low suspicious sonographic featuresobservation is an alternative
-
-
FNA is not required for:nodules not meeting above criteriapurely cystic nodules
High risk factors:
history of childhood head and neck irradiationfamily history of thyroid cancer or a thyroid cancer syndromeprior hemithyroidectomy with discovery of thyroid cancerincreased activity on PET scan-
presence ofMEN2-associated oncogene
Management of FNA results
- benign: clinical and imaging follow up
- follicular neoplasm
- require excisional biopsy because of overlap between
- hyperplastic nodule
- follicular adenoma
- follicular carcinoma
- follicular variant of papillary carcinoma
- require excisional biopsy because of overlap between
- atypia of uncertain significance / follicular lesion of uncertain significance (AUS/FLUS)
- 3-6%
- repeat FNA
- two samples obtained at second biopsy
- if AUS/FLUS again (~20%) on the first sample, then the risk of malignancy is 5-15% 10
- the second sample may be sent for gene sequencing, if available (gene expression classifier)
- if benign, then normal clinical and imaging follow up
- if suspicious, 50% risk of malignancy
- malignant: partial or total thyroidectomy with lymph node exploration
Staging
-<li>size criteria are controversial</li>-<li>cervical <a href="/articles/lymph-node-enlargement">lymphadenopathy</a> is a suspicious feature</li>- +<li>size criteria are controversial and continously evolving</li>
- +<li>cervical <a href="/articles/lymph-node-enlargement">lymphadenopathy</a> is a feature</li>
-</ul><h5>Nuclear medicine</h5><p>A single 'cold' nodule has a 10% chance of being malignant. A single 'hot' nodule has <1% chance of being malignant.</p><h4>Treatment and prognosis</h4><h5>Indications for FNA</h5><p>Indications for FNA according to <strong>Society of Radiologists in Ultrasound </strong>(2008) <sup>4</sup></p><ul>- +</ul><h5>Nuclear medicine</h5><p>A single 'cold' nodule has a 10% chance of being malignant. A single 'hot' nodule has <1% chance of being malignant.</p><h4>Treatment and prognosis</h4><h5>Indications for FNA</h5><p>The criteria developed by the <strong>American Thyroid Association</strong> (2015) <sup>11</sup> are often used in clinical practice. See: <a title="ATA guidelines for assessment of thyroid nodules" href="/articles/ata-guidelines-for-assessment-of-thyroid-nodules">ATA guidelines for assessment of thyroid nodules</a>.</p><p>Indications for FNA according to <strong>Society of Radiologists in Ultrasound </strong>(2008) <sup>4</sup></p><ul>
-</ul><p>Additional recommendations for FNA by the American Association of Clinical Endocrinologists <sup>4</sup>:</p><ul><li>FNA recommended for nodules <`10 mm whenever clinical information or ultrasound features raises suspicion about the presence of a malignancy</li></ul><p>Size criteria for indication for FNA according <strong>American Thyroid Association</strong> (2015) <sup>11</sup>:</p><ul>-<li>FNA is recommended for:<ul>-<li>nodules ≥1 cm with highly or intermediately suspicious sonographic features</li>-<li>nodules ≥1.5 cm with low suspicious sonographic features</li>-</ul>-</li>-<li>FNA may be considered for:<ul><li>nodules ≥2 cm with very low suspicious sonographic features<ul><li>observation is an alternative</li></ul>-</li></ul>-</li>-<li>FNA is not required for:<ul>-<li>nodules not meeting above criteria</li>-<li>purely cystic nodules</li>-</ul>-</li>-</ul><p>High risk factors:</p><ul>-<li>history of childhood head and neck irradiation</li>-<li>family history of thyroid cancer or a thyroid cancer syndrome</li>-<li>prior hemithyroidectomy with discovery of thyroid cancer</li>-<li>increased activity on PET scan</li>-<li>presence of <a title="MEN II" href="/articles/multiple-endocrine-neoplasia-type-ii-1">MEN2</a>-associated oncogene</li>-</ul><h5>Management of FNA results</h5><ul>- +</ul><p>Additional recommendations for FNA by the American Association of Clinical Endocrinologists <sup>4</sup>:</p><ul><li>FNA recommended for nodules <`10 mm whenever clinical information or ultrasound features raises suspicion about the presence of a malignancy</li></ul><p> </p><h5>Management of FNA results</h5><ul>
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