Assessment of thyroid lesions (general)

Dr Derek Smith and Dr Jeremy Jones et al.

Assessment of thyroid lesions is commonly encountered in radiological practice.

Thyroid mass
Risk factors for malignancy
  • 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

  • taller-than-wide in axial/transverse dimension, microcalcifications, local invasiveness, microlobulated contour, and hypoechogenicity are suspicious features
  • size criteria are controversial and continuously evolving
  • cervical lymphadenopathy is a feature
  • 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
Management of FNA results
  • benign: clinical and imaging follow-up
  • follicular neoplasm
  • 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
Thyroid pathology
Share article

Article information

rID: 2183
Synonyms or Alternate Spellings:
  • Thyroid neoplasms
  • Thyroid lesions
  • Assessing thyroid lesions

Support Radiopaedia and see fewer ads

Cases and figures

  • Case 1: miliary thyroid cancer metastases
    Drag here to reorder.
  • Coronal CT
    Case 2: papillary carcinoma
    Drag here to reorder.
  • Case 3: thyroid lymphoma
    Drag here to reorder.
  • Case 4: colloid cyst of thyroid
    Drag here to reorder.
  • Case 5: colloid nodule - ultrasound
    Drag here to reorder.
  • Thyroid lymphoma ...
    Case 6: thyroid lymphoma
    Drag here to reorder.
  • Case 7: thyroid adenoma on nuclear imaging
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.