A thyroid ultrasound in a 38-year-old woman incidentally detects a 1.2 cm solitary thyroid nodule. Features that most strongly favor malignancy on ultrasound include:

• A Well-defined margins, isoechogenicity, and peripheral rim calcification
• B Taller-than-wide shape, irregular margins, microcalcifications, and marked hypoechogenicity ✓
• C Spongiform appearance with multiple small cystic spaces
• D Comet-tail artifacts within a cystic component

Explanation

The high-risk ultrasound features of thyroid malignancy (particularly papillary carcinoma) include a taller-than-wide orientation (anteroposterior diameter exceeding transverse diameter), irregular or spiculated margins, microcalcifications (reflecting psammoma bodies), marked hypoechogenicity compared to strap muscles, and extrathyroidal extension. These features correlate with the TIRADS 5 category and necessitate fine-needle aspiration biopsy. A spongiform appearance and comet-tail artifacts are highly reassuring benign features. Peripheral eggshell calcification, while sometimes benign, can be seen with medullary carcinoma.

Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.