Thyroid carcinoma encompasses several types of thyroid cancer, with papillary carcinoma being the most common (about 80 percent), followed by follicular, medullary, and anaplastic carcinoma. On ultrasound, features that raise suspicion for malignancy in a thyroid nodule include solid composition, hypoechogenicity, microcalcifications (tiny bright dots), irregular or spiculated margins, a taller-than-wide shape, and evidence of extrathyroidal extension. The TI-RADS scoring system assigns points based on these features to determine whether a nodule warrants biopsy. Not all thyroid cancers display all suspicious features, and some cancers can appear relatively benign on ultrasound, which is why biopsy thresholds are based on a combination of features and size. Ultrasound also evaluates cervical lymph nodes for signs of metastatic disease.
Sonography Term