US Features of thyroid malignancy: pearls and pitfalls

Radiographics. 2007 May-Jun;27(3):847-60; discussion 861-5. doi: 10.1148/rg.273065038.


Thyroid nodules are common and occur in up to 50% of the adult population; however, less than 7% of thyroid nodules are malignant. High-resolution ultrasonography (US) is commonly used to evaluate the thyroid gland, but US is frequently misperceived as unhelpful for identifying features that distinguish benign from malignant nodules. Microcalcifications are one of the most specific US findings of a thyroid malignancy. Other useful US features include a marked hypoechogenicity, irregular margins, and the absence of a hypoechoic halo around the nodule. Lymphadenopathy and local invasion of adjacent structures are highly specific features of thyroid malignancy but are less commonly seen. The number, size, and interval growth of nodules are nonspecific characteristics. Suspicious US features may be useful for selecting patients for fine-needle aspiration biopsy when incidental nodules are discovered and when multiple nodules are present. Common interpretative pitfalls that may lead to failure to recognize a malignancy include mistaking cystic or calcified nodal metastases for nodules in a multinodular thyroid, mistaking diffusely infiltrative thyroid carcinomas and multifocal carcinomas for benign disease, and failing to recognize microcalcifications in papillary thyroid cancer.

Publication types

  • Case Reports
  • Review

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Diagnosis, Differential
  • Diagnostic Errors / prevention & control*
  • Female
  • Humans
  • Image Enhancement / methods*
  • Male
  • Middle Aged
  • Practice Guidelines as Topic
  • Practice Patterns, Physicians'
  • Sensitivity and Specificity
  • Thyroid Neoplasms / diagnostic imaging*
  • Ultrasonography / methods*